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electrochemical genosensor array for the simultaneous detection of multiple high-risk human papillomavirus sequences in clinical samples.an electrochemical genosensor array for the simultaneous detection of three high-risk human papillomavirus (hpv) dna sequences, hpv16, 18 and 45, exhibiting high sensitivity and selectivity is presented. the electrodes of a 4×4 array were modified via co-immobilization of a 1:100 (mol/mol) mixture of a thiolated probe and an oligoethyleneglycol-terminated bipodal thiol. detection of synthetic and pcr products was carried out in a sandwich type format, with the target hybridized between a surface ...201222244172
colorimetric assay for t4 polynucleotide kinase activity based on the horseradish peroxidase-mimicking dnazyme combined with λ exonuclease cleavage.t4 polynucleotide kinase (pnk) plays a critical role in various cellular events. here, we describe a novel colorimetric strategy for estimating the activity of pnk and screening its inhibitors taking advantage of the efficient cleavage of λ exonuclease and the horseradish peroxidase-mimicking dnazyme (hrpzyme) signal amplification. a label-free hairpin dna with the sequence of hrpzyme was utilized in the assay. the 5'-hydroxyl terminal of the hairpin dna was firstly phosphorylated in the presenc ...201223427805
rostral ventromedial medulla connections in cavia porcellus and their relation with tonic immobility defensive behavior: a biotinylated dextran amine neurotracing study.the rostroventromedial medulla (rvm), together with the periaqueductal gray matter (pag), constitutes the descendent antinociceptive system. additionally, these structures mutually regulate defensive behaviors, including tonic immobility (ti) in guinea pigs. the current study was undertaken to evaluate the connections of the rvm with the pag and the spinal cord in guinea pigs in order to provide an anatomical basis for the role played by rvm in the modulation of ti. to address this goal, five gu ...201223287522
diverse release behaviors of water-soluble bioactive substances from fibrous membranes prepared by emulsion and suspension electrospinning.time-programmed release behaviors of different bioactive substances, enough mechanical properties and good biocompatibility of the scaffold play an important role in vascular tissue regeneration. in this paper, ultrafine fibers with diverse release behaviors were prepared by emulsion or suspension electrospinning from poly(l-lactide-co-glycolide) (plga) or poly(ethylene glycol)-b-poly(l-lactide-co-caprolactone) (pelcl), designated as e-plga, eh-plga, and eh-pelcl, respectively. chitosan hydrogel ...201223713426
a self-assemble aptamer fragment/target complex based high-throughput colorimetric aptasensor using enzyme linked aptamer assay.enzyme linked aptamer assay (elaa) uses an aptamer as recognition element and enzyme as signal readout element for establishing different kinds of aptasensors. we reported herein a high-throughput colorimetric aptasensor based on elaa only requiring a single aptamer sequence for cocaine detection. an anti-cocaine aptamer was cleaved into two fragments, one of which was immobilized on a dna-bind 96-well plate via 5'-labeled primary amine and the other one was biotin labeled. the presence of two a ...201223598133
quantum dot-based fret for sensitive determination of hydrogen peroxide and glucose using tyramide reaction.in this paper, we report a new strategy for detection of hydrogen peroxide and glucose using quantum dot (qd)-based fluorescence resonance energy transfer (fret) and tyramide reaction. the principle of fret is based on highly sensitive reaction of a carbocyanine dye (cy5) labeled tyramide and hydrogen peroxide catalyzed by horseradish peroxidase (hrp), and the fluorescence spectrum of qds (exmax 605 nm) partially overlaps with the absorption bands of cy5. we firstly conjugated hrp to qds, and th ...201223598098
sensitive detection of cd147/emmprin and its expression on cancer cells with electrochemical technique.cluster of differentiation 147 (cd147), also known as extracellular matrix metalloproteinase inducer (emmprin), plays an essential role in tumor progression and metastasis, the expression of which on cell surface is a critical clinical testing index for cancer therapy. in this work, an electrochemical method to assay cd147/emmprin expression on tumor cell surface is proposed. while the oxidation of 3,3',5,5'-tetramethylbenzidine (tmb) catalyzed by horseradish peroxidase (hrp) can be employed for ...201223598007
the interaction of diamines and polyamines with the peroxidase-catalyzed metabolism of aromatic amines: a potential mechanism for the modulation of aniline toxicity.synthetic and biological amines such as ethylenediamine (eda), spermine, and spermidine have not been previously investigated in free-radical biochemical systems involving aniline-based drugs or xenobiotics. we aimed to study the influence of polyamines in the modulation of aromatic amine radical metabolites in peroxidase-mediated free radical reactions. the aniline compounds tested caused a relatively low oxidation rate of glutathione in the presence of horseradish peroxidase (hrp), and h2o2; h ...201223537436
[screening and characterization of aptamers of cepsilon3-cepsilon4 protein].in order to obtain nucleotides aptamers bind to ige, 80 bp nucleotides single-stranded dna library containing 40 random nucleotides was designed and synthesized. oligonucleotides that bind to human cepsilon3-cepsilon4 protein were isolated from ssdna pools by the systematic evolution of ligands by exponential enrichment (selex) method using nitrocellulose filters as screening medium. through the optimization of critical pcr and asymmetric pcr parameters including annealing temperature, cycles, a ...201223460965
influence of different length linker containing dhea-7-cmo-enzyme conjugates on sensitivity and specificity of dhea-3-hs-antibody.the introduction of spacers in coating steroid antigen or enzyme conjugates or immunogen is known to exert an influence on the sensitivity of steroid enzyme immunoassays. we have introduced different homobifunctional spacers having varying atomic length (3 to 10) between enzyme and dehydroepiandrosterone (dhea) moiety and studied their effects on functional parameters such as sensitivity and specificity of dhea enzyme immunoassays. dhea-3-hemisuccinate-bovine serum albumin (dhea-3-hs-bsa) was us ...201222181816
morphophysiological characteristics of connexions between single ventrolateral tract fibres and individual motoneurones in the frog spinal cord.in experiments on the isolated frog spinal cord, simultaneous intracellular recordings were performed from synaptically connected individual ventrolateral tract fibres and lumbar motoneurones. statistical parameters of amplitude fluctuations of unitary excitatory postsynaptic potentials evoked by direct activation of presynaptic axons were compared with the number of synaptic contacts at the same connexions revealed by staining both pre- and postsynaptic elements with horseradish peroxidase. clo ...20123567653
specificity of neuromuscular connections during early development and following regeneration of motor axons in the bullfrog.the specificity of neuromuscular connectivity was examined in unoperated bullfrog (rana catesbeiana) tadpoles and in tadpoles that had undergone transection of the three ventral roots that normally innervate the hindlimb. the specificity of motoneuron projections was assessed by applying small amounts of horseradish peroxidase to circumcribed hindlimb regions and mapping the locations of retrogradely labeled motoneurons within the lumbar lateral motor column (lmc). in unoperated tadpoles, the lo ...20123498135
afferent and efferent innervation patterns of the cochlear nucleus (dorsal medullary nucleus) of the leopard frog.the afferent and efferent innervation patterns of the frog dorsal medullary nucleus (dmn; anuran homolog of the cochlear nucleus) were examined by studying the anterograde and retrograde transport patterns of horseradish peroxidase injected focally into the nucleus. it was found that this structure projected bilaterally to the superior olivary nuclei (son) and dorsal midbrain tegmental nuclei, and contralaterally to the opposite dmn, the lateral lemniscus nucleus (lln) and the torus semicircular ...20123486022
role of muscle neurotization in the reinnervation of murine muscle grafts.although the reinnervation of muscle grafts has been demonstrated, the question remains as to the source of neurons reinnervating the graft. a muscle graft could be reinnervated by its original neurons (neural neurotization) or by sprouting of axons which supply the intact myofibers of surrounding muscles (muscle neurotization). the objective of this study was to evaluate the role of muscle neurotization in the reinnervation process using both horseradish peroxidase and fluorescent tracers. obse ...20123448953
on the presence of nucleus ruber in the urodele salamandra salamandra and the caecilian ichthyophis kohtaoensis.the presence of nucleus ruber in urodeles and caecilians (amphibia) was investigated. for that purpose, horseradish peroxidase was applied to the rostral spinal cord, the medulla oblongata at various levels and the dorsolateral funiculus. whereas salamandra salamandra possesses a rubrospinal tract, it is absent in the limbless caecilian ichthyophis kohtaoensis.20123382518
topography of interhemispheric connections in neocortex of mice with congenital deficiencies of the callosal commissure.normally, axons within the corpus callosum are ordered according to the cortical regions from which they originate, and callosal cells and terminations form elaborate cortical patterns related to the underlying topographic representations of the sensory periphery. about 30% of mice of the balb/c strain show congenital deficiencies of the callosal commissure which range from total absence of the corpus callosum to a moderate reduction in the size of this commissure. in the light of current theori ...20123372749
endocytosis in the embryonic chick chorionic epithelium.the chorionic epithelium of the developing chick embryo consists of two major cell types, villus cavity (vc) and sinus-covering (sc) cells. ultrastructurally, vc cells contain apical microvilli with numerous underlying vesicles, whereas sc cells possess thin cytoplasmic processes (containing occasional vesicles) overlying adjacent blood sinuses. this study was performed to determine whether vesicles observed in vc and sc cells are endocytic in nature and whether endocytosis is limited to either ...20123298539
identification of the teleost edinger-westphal nucleus by retrograde horseradish peroxidase labeling and by electrophysiological criteria.a homolog of the edinger-westphal nucleus of other vertebrates is described in two species of serranid basses of the genus paralabrax, a group possessing a wide range of ocular accommodation but lacking a pupillary reflex to light. the nucleus was found by retrograde labeling from the ciliary ganglion and lies dorsolateral to the ipsilateral oculomotor nucleus. the nucleus consists of 60 to 100 neurons with an average soma diameter of about 20 microns in animals weighing 70 to 150 g. electrophys ...20123361460
surface and intracellular distribution of a putative neuronal nicotinic acetylcholine receptor.chick ciliary ganglion neurons have a membrane component that shares an antigenic determinant with the main immunogenic region (mir) of nicotinic acetylcholine receptors from skeletal muscle and electric organ. previous studies have shown that the component has many of the properties expected for a ganglionic nicotinic acetylcholine receptor, and that its distribution on the neuron surface in vivo is restricted predominantly to synaptic membrane. here we report the presence of a large intracellu ...20123522604
visualization of the multimeric structure of von willebrand factor using a peroxidase-conjugated second antibody.we describe a technique for visualizing the multimeric structure of von willebrand factor that does not require use of radioisotopes. this procedure uses a previously described discontinuous dodecyl sulfate agarose gel electrophoretic method followed by transfer of the protein to a nitrocellulose filter and detection by a double-antibody technique in which the second antibody is conjugated to horseradish peroxidase. in the presence of h2o2 and 4-chloro-1-napthol, the antigen appears as a series ...20123511161
connections of the tectum opticum in two urodeles, salamandra salamandra and bolitoglossa subpalmata, with special reference to the nucleus isthmi.tectal connections were studied in two urodele species following horseradish peroxidase injections into the tectum opticum. in both species retrogradely labelled cells were observed: ipsilaterally in the corpus striatum, lateral amygdala, ventral and dorsal thalamus and nucleus of darkschewitsch--bilaterally in the pretectal nucleus, dorsal tegmentum and nucleus reticularis medius--contralaterally in the tectum opticum and area octavo lateralis. besides these nuclei the nucleus isthmi was bilate ...20123385198
peroxidase-catalyzed stabilization of 2,4-dichlorophenol in alkali-extracted soils.horseradish peroxidase- (hrp) mediated stabilization of phenolic contaminants is a topic of interest due to its potential for remediation of contaminated soils. this study evaluated the sorption of 2,4-dichlorophenol (dcp) and its hrp-mediated stabilization in two alkali-extracted soils. alkali extraction reduced the soil organic matter (som) contents of the geomaterials and enriched the residual som with humin c. sorption of dcp on these sorbents was complete within 1 d. however, most of the so ...201221488501
phytochemical composition, antioxidant activity, and neuroprotective effect of terminalia chebula retzius extracts.the objectives of this study were to determine phytochemical compositions, chemiluminescence antioxidant activities, and neuroprotective effects on pc12 cells for water, methanol, and 95% ethanol extracts of the air-dried fruit of terminalia chebula retzius. the water extract afforded the greatest yield, and total phenolic and tannin content. the methanol extract yielded the greatest total triterpenoid content. based on four chemiluminescence antioxidant assays, the three extracts showed various ...201221754945
phytochemical characteristics, free radical scavenging activities, and neuroprotection of five medicinal plant extracts.the objective of this study was to determine phytochemical characteristics, chemiluminescence antioxidant capacities, and neuroprotective effects on pc12 cells for methanol extracts of spatholobus suberectus, uncaria rhynchophylla, alpinia officinarum, drynaria fortunei, and crataegus pinnatifida. the c. pinnatifida extract (cpe) afforded the greatest yield and total phenolic content. the s. suberectus extract (sse) yielded the greatest total flavonoid content. the u. rhynchophylla extract (ure) ...201221845204
differential effects of nutritional and non-nutritional therapies on intestinal barrier function in an in vitro model.diminished intestinal epithelial barrier function contributes to the pathogenesis of crohn's disease. clinical and experimental studies propose that increased tumor necrosis factor (tnf)-α promotes barrier dysfunction. the aim of this study was to investigate the effects of nutritional and other therapies upon intestinal barrier function in the presence of tnf-α in an in vitro model.201221953313
occupational ige-mediated softwood allergy: characterization of the causative allergen.allergic reactions to wood dust allergens are rare, and only few in vitro diagnostic tools and information about relevant allergens are available. to differentiate between protein-based allergy and probably clinically silent glycogenic sensitization, it is helpful to characterize the relevant protein allergens and specify ige binding. the current case report deals with the occupational softwood allergy of a carpenter exposed to different wood dusts. skin tests and ige tests against wood were per ...201221986217
layer-by-layer construction of protein architectures through avidin-biotin and lectin-sugar interactions for biosensor applications.in this review, the preparation and properties of protein architectures constructed by layer-by-layer (lbl) deposition through avidin-biotin and concanavalin a (con a)-sugar interactions are discussed in relation to their use for optical and electrochemical biosensors. lbl films can be constructed through the alternate deposition of avidin and biotin-labeled enzymes on the surfaces of optical probes and electrodes. the enzymes retain their catalytic activity, resulting in the formation of optica ...201221866404
a amperometric biosensor for hydrogen peroxide by adsorption of horseradish peroxidase onto single-walled carbon nanotubes.development of a highly sensitive nanostructured electrochemical biosensor based on the integrated assembly of horseradish peroxidase (hrp) and single-walled carbon nanotubes (swnts) is described. in this study, we describe the use of a sodium cholate suspension-dialysis method to adsorb the horseradish peroxidase (hrp) onto single-walled carbon nanotubes (swnts). we demonstrate that hrp-swnts conjugates can be assembled into amperometric biosensors which l-cysteine were assembled on a gold elec ...201222019049
a novel approach to construct a horseradish peroxidase|hydrophilic ionic liquids|au nanoparticles dotted titanate nanotubes biosensor for amperometric sensing of hydrogen peroxide.the direct electrochemistry of horseradish peroxidase (hrp) on a novel sensing platform modified glassy carbon electrode (gce) has been achieved. this sensing platform consists of nafion, hydrophilic room-temperature ionic liquid (rtil) and au nanoparticles dotted titanate nanotubes (gnps-tnts). the composite of rtil and gnps-tnts was immobilized on the electrode surface through the gelation of a small amount of hrp aqueous solution. the composite was characterized by transmission electron micro ...201222024591
nanomolar hydrogen peroxide detection using horseradish peroxidase covalently linked to undoped nanocrystalline diamond surfaces.in this article, we report on the low-level detection of hydrogen peroxide, a key player in the redox signaling pathway and a toxic product in the cellular system, using a colorimetric solution assay. amine-terminated undoped nanocrystalline diamond thin films were grown on glass using a linear-antenna microwave plasma cvd process. the diamond surface consists mainly of -nh(2) termination. the aminated diamond surface was decorated with horseradish peroxidase (hrp) enzyme using carbodiimide coup ...201222066858
peroxidase-mediated dealkylation of tamoxifen, detected by electrospray ionization-mass spectrometry, and activation to form dna adducts.tamoxifen (tam) is extensively used for the treatment and prevention of breast cancer. associated with tam treatment is a two- to eightfold increase in risk of endometrial cancer. to understand the mechanisms associated with this increased risk several pathways for tam metabolism and dna adduct formation have been studied. the purpose of this study was to investigate the role of peroxidase enzymes in the metabolism of tam and its activation to form dna adducts. using advanced tandem mass spectro ...201222064363
simultaneous electrochemical detection of multiple analytes based on dual signal amplification of single-walled carbon nanotubes and multi-labeled graphene sheets.in this work, a sandwich-type electrochemical aptasensor for simultaneous sensitive detection of platelet-derived growth factor (pdgf) and thrombin is fabricated. reduced graphene oxide sheets (rgs) are used as matrices to immobilize the redox probes, which are subsequently coated with platinum nanoparticles (ptnps) to form the ptnps-redox probes-rgs nanocomposites. with the employment of the as prepared nanocomposites, a signal amplification strategy was described based on bienzyme (glucose oxi ...201222061494
live diatom silica immobilization of multimeric and redox-active enzymes.living organisms are adept in forming inorganic materials (biominerals) with unique structures and properties that exceed the capabilities of engineered materials. biomimetic materials syntheses are being developed that aim at replicating the advantageous properties of biominerals in vitro and endow them with additional functionalities. recently, proof-of-concept was provided for an alternative approach that allows for the production of biomineral-based functional materials in vivo. in this appr ...201222057862
combinatorial glycoarray.glycolipid-protein interactions are increasingly recognised as critical to numerous and diverse biological processes, including immune recognition, cell-cell signalling, pathogen adherence, and virulence factor binding. previously, such carbohydrate-lectin interactions have been assessed in vitro largely by assaying protein binding against purified preparations of single glycolipids. recent observations show that certain disease-associated autoantibodies and other lectins bind only to complexes ...201222057541
assembly of graphene oxide-enzyme conjugates through hydrophobic interaction.biochemical and biomedical applications of graphene oxide (go) critically rely on the interaction of biomolecules with it. it has been previously reported that the biological activity of the go-enzyme conjugate decreases due to electrostatic interaction between the enzymes and go. herein, the immobilization of horseradish peroxidase (hrp) and oxalate oxidase (oxox) on chemically reduced graphene oxide (crgo) are reported. the enzymes can be adsorbed onto crgo directly with a tenfold higher enzym ...201222038754
3-glycidoxypropyltrimethoxysilane mediated in situ synthesis of noble metal nanoparticles: application to hydrogen peroxide sensing.the in situ synthesis is reported of noble metal nanoparticles via 3-glycidoxypropyltrimethoxysilane mediated reduction of 3-aminopropyltrimethoxysilane treated metal salts during sol-gel processing. the method described involves the synthesis of uniform spherical nanoparticles of gold, silver and palladium with controlled size that can be directly utilized for thin film preparation. a detailed study of the synthesis and application of gold nanoparticles to the electrochemical detection of hydro ...201222081133
chemiluminescence biosensors for dna detection using graphene oxide and a horseradish peroxidase-mimicking dnazyme.in this communication, we demonstrate that graphene oxide (go) greatly inhibits the peroxidatic activity of a horseradish peroxidase-mimicking dnazyme. combining this observation with the unique dna/go interactions, an ultrasensitive go-based chemiluminescence dna biosensing platform is developed.201222167008
hollow mesoporous silica microspheres as sensitive labels for immunoassay of prostate-specific antigen.a novel electrochemical immunosensor for sensitive detection of cancer biomarker prostate-specific antigen (psa) has been reported based on nanoporous gold (npg) and hollow mesoporous silica microspheres (hsms). the immunoassay was conducted by following the typical procedure for sandwich-type immunoreaction. nanoporous gold (npg) foils were immobilized onto a glassy carbon electrode (gce) for primary anti-psa (ab(1)) anchoring. making use of the unique properties of npg, antibodies could be sel ...201222166957
kinetic approach of aflatoxin b1-acetylcholinesterase interaction: a tool for developing surface plasmon resonance biosensors.this work presents a kinetic approach of the interaction between acetylcholinesterase (ache) from electric eel and aflatoxin b1 (afb1) or its protein conjugate (e.g., afb1-hrp [horseradish peroxidase]) in order to develop a simple and sensitive detection method of these compounds. the dissociation constant k(d) of the ache/afb1-hrp interaction (0.4 μm) obtained with the surface plasmon resonance (spr) technique is very close to the inhibition constant reported in amperometric assay (k(i)=0.35 μm ...201222093609
sensitive electrochemical immunosensor array for the simultaneous detection of multiple tumor markers.a novel electrochemical immunosensor array for the simultaneous detection of multiple tumor markers was developed by incorporating electrochemically addressing immobilization and one signal antibody strategy. as a proof-of-principle, an eight-electrode array including six carbon screen-printed working electrodes was used as a base array for the analysis of two important tumor markers, carcinoembryonic antigen (cea) and α-fetoprotein (afp) and a horseradish peroxidase-labeled antibody was employe ...201222091469
1,1'-oxalyldiimidazole chemiluminescent enzyme immunoassay capable of simultaneously sensing multiple markers.in order to rapidly and simultaneously quantify and screen trace levels of multiple biomarkers in a single sample, rapid 1,1'-oxalyldiimidazole chemiluminescence (odi cl) was applied as a biosensor of immunoassays using various enzymes such as alkaline phosphatase (alp) and horseradish peroxidise (hrp). (1) fluorescein was formed from the reaction of fluorescein diphosphate (fdp) and immuno-complex conjugated with alp. (2) resorufin was formed from the reaction between amplex red and h(2)o(2) in ...201222088260
an electrochemical aptasensor based on enzyme linked aptamer assay.an aptamer is an artificial functional oligonucleic acid, which can interact with its target molecule with high affinity and specificity. enzyme linked aptamer assay (elaa) is developed to detect cocaine using aptamer fragment/cocaine configuration based on the affinity interaction between aptamer fragments with cocaine. the aptasensor was constructed by cleaving anticocaine aptamer into two fragments: one was assembled on a gold electrode surface, while the other was modified with biotin at 3'- ...201222100766
pd nanoparticle assemblies--as the substitute of hrp, in their biosensing applications for h2o2 and glucose.the spherical porous pd nanoparticle assemblies (npas) have been successfully synthesized by starch-assisted chemical reduction of pd(ii) species at room temperature. such pd npas are not simply used to enlarge the surface area and to promote the electron transfer. they also catalyze the reduction of h(2)o(2) which are regarded as horseradish peroxidase (hrp) substitutes in electron transfer process. by using them as electrocatalysts, as low as 6.8×10(-7) m h(2)o(2) can be detected with a linear ...201222100764
paracellular versus transcellular intestinal permeability to gliadin peptides in active celiac disease.the intestinal permeability of undegraded α9-gliadin peptide 31-49 (p31-49) and 33-mer gliadin peptides is increased in active celiac disease. two distinct transport pathways have been proposed: paracellular leakage through epithelial tight junctions and protected transcellular transport. to analyze the relative contribution of these pathways, we compared mucosa-to-serosa permeability of small and large permeability markers [ionic conductance (g), mannitol, 182 da; horseradish peroxidase, 40 kda ...201222119716
fabrication of immunosensor microwell arrays from gold compact discs for detection of cancer biomarker proteins.a simple method is reported to fabricate gold arrays featuring microwells surrounding 8-electrodes from gold compact discs (cds) for less than $0.2 per chip. integration of these disposable gold cd array chips with microfluidics provided inexpensive immunoarrays that were used to measure a cancer biomarker protein quickly at high sensitivity. the gold cd sensor arrays were fabricated using thermal transfer of laserjet toner from a computer-printed pattern followed by selective chemical etching. ...201222116194
reactive metabolites of desipramine and clomipramine: the kinetics of formation and reactivity with dna.tricyclic antidepressants (tcas), along with phenothyazines and some industrial chemicals, are shown to react with enzymes that exhibit peroxidase activity. these reactions result in the formation of reactive intermediates having unpaired electrons. the peroxidase oxidation and reactivity of two tcas, desipramine and clomipramine, were investigated. as a model of peroxidase, horseradish peroxidase (hrp) was employed. the products of the peroxidase catalyzed oxidation of desipramine and clomipram ...201222115837
a proteomics approach to the cell-surface interactome using the enzyme-mediated activation of radical sources reaction.we previously reported a simple method to analyze the interaction of cell-surface molecules in living cells. this method termed enzyme-mediated activation of radical sources (emars) is featured by radical formation of the labeling reagent by horseradish peroxidase (hrp). herein, we propose an approach to the cell-surface molecular interactome by using combination of this emars reaction and ms-based proteomics techniques. in the current study, we employed a novel labeling reagent, fluorescein-con ...201222106087
ultrasensitive detection of phenolic compounds based on a spin-labeled luminescent lanthanide complex.herein we propose a novel method for ultrasensitive detection of phenolic compounds. this method was developed based on a spin-labeled terbium complex tb(3+)/cs124-dtpa-tempo (1). this spin-labeled terbium complex is a weakly luminescent compound and shows strong off-on luminescent response to phenolic compounds in the presence of horseradish peroxidase (hrp), glutathione (gsh) and hydrogen peroxide. the analyte recognition and signaling mechanism are discussed and the factors affecting the off- ...201222140675
global profiling of reactive oxygen and nitrogen species in biological systems: high-throughput real-time analyses.herein we describe a high-throughput fluorescence and hplc-based methodology for global profiling of reactive oxygen and nitrogen species (ros/rns) in biological systems. the combined use of hplc and fluorescence detection is key to successful implementation and validation of this methodology. included here are methods to specifically detect and quantitate the products formed from interaction between the ros/rns species and the fluorogenic probes, as follows: superoxide using hydroethidine, pero ...201222139901
nano reengineering of horseradish peroxidase with dendritic macromolecules for stability enhancement.a simple bio-conjugation procedure to surround a single horseradish peroxidase (hrp) enzyme molecule with dendritic polyester macromolecules (polyester-32-hydroxyl-1-carboxyl bis-mpa dendron, generation 5) was proposed. the characterization of resultant nanoparticles entitled hrp dendrozyme, was performed by transmission electron microscopy, dynamic light scattering, gel permeation chromatography and fourier transform infrared spectroscopy. the results showed that hrp nanoparticles were spherica ...201222133434
biodegradation and in vitro biocompatibility of polyperoxides: alternating co-polymers of vinyl monomers and molecular oxygen.vinyl polyperoxides, alternating co-polymers of vinyl monomers and molecular oxygen, are a small but important class of polymers with unique properties, such as highly exothermic degradation in contrast to common polymers, which generally show endothermic degradation. enzymatic degradation and in vitro biocompatibility have been studied for the vinyl polyperoxides polystyrene peroxide (psp), poly(α- methylstyrene) peroxide (pamsp) and poly(methyl methacrylate) peroxide (pmmap). enzymatic degrada ...201222152546
enzyme reactions in nanoporous, picoliter volume containers.advancements in nanoscale fabrication allow creation of small-volume reaction containers that can facilitate the screening and characterization of enzymes. a porous, ∼19 pl volume vessel has been used in this work to carry out enzyme reactions under varying substrate concentrations. assessment of small-molecule and green fluorescent protein diffusion from the vessels indicates that pore sizes on the order of 10 nm can be obtained, allowing capture of proteins and diffusive exchange of small mole ...201222148720
hydroxyl radical-induced oxidation of a phenolic c-linked 2'-deoxyguanosine adduct yields a reactive catechol.phenolic toxins stimulate oxidative stress and generate c-linked adducts at the c8-site of 2'-deoxyguanosine (dg). we previously reported that the c-linked adduct 8-(4″-hydroxyphenyl)-dg (p-phoh-dg) undergoes oxidation in the presence of na(2)ircl(6) or horseradish peroxidase (hrp)/h(2)o(2) to generate polymeric adducts through phenoxyl radical production [ weishar ( 2008 ) org. lett. 10 , 1839 - 1842 ]. we now report on reaction of p-phoh-dg with two radical-generating systems, cu(ii)/h(2)o(2) ...201222176608
magnetic bead-sensing-platform-based chemiluminescence resonance energy transfer and its immunoassay application.a competitive immunoassay based on chemiluminescence resonance energy transfer (cret) on the magnetic beads (mbs) is developed for the detection of human immunoglobulin g (igg). in this protocol, carboxyl-modified mbs were conjugated with horseradish peroxidase (hrp)-labeled goat antihuman igg (hrp-anti-igg) and incubated with a limited amount of fluorescein isothiocyanate (fitc)-labeled human igg to immobilize the antibody-antigen immune complex on the surface of the mbs, which was further incu ...201222339489
enzyme-regulated activation of dnazyme: a novel strategy for a label-free colorimetric dna ligase assay and ligase-based biosensing.the dna nick repair catalyzed by dna ligase is significant for fundamental life processes, such as the replication, repair, and recombination of nucleic acids. here, we have employed ligase to regulate dnazyme activity and developed a homogeneous, colorimetric, label-free and dnazyme-based strategy to detect dna ligase activity. this novel strategy relies on the ligation-trigged activation or production of horseradish peroxidase mimicking dnazyme that catalyzes the generation of a color change s ...201222337073
enhanced enzyme activity through electron transfer between single-walled carbon nanotubes and horseradish peroxidase.better understanding of electron transfer (et) taking place at the nano-bio interface can guide design of more effective functional materials used in fuel cells, biosensors, and medical devices. single-walled carbon nanotube (swcnt) coupled with biological enzymes serves as a model system for studying the et mechanism, as demonstrated in the present study. swcnt enhanced the activity of horseradish peroxidase (hrp) in the solution-based redox reaction by binding to hrp at a site proximate to the ...201222228910
two-step oxidation of glycerol to glyceric acid catalyzed by the phanerochaete chrysosporium glyoxal oxidase.glyoxal oxidase of p. chrysosporium is a radical copper oxidase that catalyzes oxidation of aldehydes to carboxylic acids coupled to dioxygen reduction to h(2)o(2). in addition to known substrates, glycerol is also found to be a substrate for glyoxal oxidase. during enzyme turnover, glyoxal oxidase undergoes a reversible inactivation, probably caused by loss of the active site free radical, resulting in short-lasting enzyme activities and undetectable substrate conversions. enzyme activity could ...201222226201
model study of the enzymatic modification of natural extracts: peroxidase-based removal of eugenol from rose essential oil.a protocol based on the use of horseradish peroxidase (hrp) is proposed for the removal of allergenic eugenol from rose essential oil without loss of the organoleptic quality and with a good conservation of the chemical composition. for the first time, an enzyme-based strategy is proposed for essential oils treatment and opens new opportunities in the detoxification of natural extracts used in perfumery and cosmetics. our results on eugenol in rose essential oil constitute a first step toward th ...201222224510
sensitive electrochemical immunosensor for α-synuclein based on dual signal amplification using pamam dendrimer-encapsulated au and enhanced gold nanoparticle labels.a novel electrochemical immunosensor for sensitive detection of α-synuclein (α-syn), a very important neuronal protein, has been developed based on dual signal amplification strategy. herein, g4-polyamidoamine dendrimer-encapsulated au nanoparticles (pamam-au nanocomposites) were covalently bound on the poly-o-aminobenzoic acid (poly-o-aba), which was initially electropolymerized on the electrode surface to perform abundant carboxyl groups. the formed immunosensor platform, pamam-au, was proved ...201222221797
aptamer-dnazyme hairpins for biosensing of ochratoxin a.we report an aptasensor for biosensing of ochratoxin a (ota) using aptamer-dnazyme hairpin as biorecognition element. the structure of this engineered nucleic acid includes the horseradish peroxidase (hrp)-mimicking dnazyme and the ota specific aptamer sequences. a blocking tail captures a part of these sequences in the stem region of the hairpin. in the presence of ota, the hairpin is opened due to the formation of the aptamer-analyte complex. as a result, self-assembly of the active hrp-mimick ...201222221796
comparison of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide based strategies to crosslink antibodies on amine-functionalized platforms for immunodiagnostic applications.1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (edc) alone, and in combination with n-hydroxysuccinimide (nhs) or sulfonhs were employed for crosslinking anti-human fetuin a (hfa) antibodies on 3-aminopropyltriethoxysilane (aptes)-functionalized surface plasmon resonance (spr) gold chip and 96-well microtiter plate. the spr immunoassay and sandwich enzyme linked immunosorbent immunoassay (elisa) for hfa clearly demonstrated that edc crosslinks anti-hfa antibodies to aptes-functionalized bioanaly ...201226859395
water-soluble electrospun nanofibers as a method for on-chip reagent storage.this work demonstrates the ability to electrospin reagents into water-soluble nanofibers resulting in a stable on-chip enzyme storage format. polyvinylpyrrolidone (pvp) nanofibers were spun with incorporation of the enzyme horseradish peroxidase (hrp). scanning electron microscopy (sem) of the spun nanofibers was used to confirm the non-woven structure which had an average diameter of 155 ± 34 nm. the hrp containing fibers were tested for their change in activity following electrospinning and du ...201225586029
mechanisms for covalent immobilization of horseradish peroxidase on ion-beam-treated polyethylene.the surface of polyethylene was modified by plasma immersion ion implantation. structure changes including carbonization and oxidation were observed. high surface energy of the modified polyethylene was attributed to the presence of free radicals on the surface. the surface energy decay with storage time after treatment was explained by a decay of the free radical concentration while the concentration of oxygen-containing groups increased with storage time. horseradish peroxidase was covalently ...201224278665
nitric oxide, substrate of euphorbia characias peroxidase, switches off the cn(-) inhibitory effect.the oxidation of nitric oxide (no) by euphorbia characias latex peroxidase (elp-fe(iii)), in the presence or in the absence of added calcium, has been investigated. the addition of hydrogen peroxide to the native enzyme leads to the formation of compound i and serves to catalyse the no oxidation. the addition of no to compound i leads to the formation of compound ii and, afterwards, to the native enzyme spectrum. under anaerobic conditions, the incubation of the native enzyme (elp-fe(iii))with n ...201223772363
[organization of the projections of the structures of the basal ganglia morpho-functional system to the individual substructures of the deep mesencephalic nucleus complex of dog brain].the method of retrograde axonal transport of horseradish peroxidase was used to study the organization of the projections of the morpho-functional system of the basal ganglia nuclei to the individual substructures of the of deep mesencephalic nucleus complex (dmnc) of dog brain (n = 9). it was found that the nucleus accumbens was the only striatum structure containing the neurons that sent projection fibers to the subcuneate nucleus. the projections of the output structures of the basal ganglia- ...201223659032
hydrogen peroxide detection at a horseradish peroxidase biosensor with a au nanoparticle-dotted titanate nanotube|hydrophobic ionic liquid scaffold.in this work, a novel sensing scaffold, consisting au nanoparticle (gnp)-dotted tio(2) nanotubes (tnts) as the rigid material and the hydrophobic ionic liquid (hil), 1-decyl-3-methylimidazolium tetrafluoroborate, as the entrapping agent, was applied to facilitate the electron transfer of horseradish peroxidase (hrp) on a glassy carbon electrode. gnps were immobilised on the tnts in our work using a one-step reduction of haucl(4)·3h(2)o by sodium borohydride in the presence of sodium citrate as a ...201222204779
highly efficient quenching of electrochemiluminescence from cds nanocrystal film based on biocatalytic deposition.aiming to find an alternative electrochemiluminescence (ecl) quenching route of high efficiency, biocatalytic precipitation (bcp) was firstly coupled with ecl for investigating its insulating effect on ecl. experimental data revealed that an insulating layer could be formed via bcp onto the electrode surface, inhibiting the reaction between the coreactant and luminophore and thereby impairing the ecl emission dramatically. since the extent of insulating effect associated strongly with analyte co ...201222284512
a novel label-free fluorescent sensor for the detection of potassium ion based on dnazyme.a novel label-free and sensitive fluorescent aptasensor for the detection of potassium ion (k(+)) was developed based on the horseradish peroxidase-mimicking dnazyme (hrp-dnazyme). in this work, we selected a k(+)-stabilized single stranded dna (ssdna) with g-rich sequence as the recognition element. in the presence of k(+), the g-rich dna folded into the g-quadruplex structure, and then hemin can bind to the g-quadruplex structure as a co-factor and form hrp-dnazyme. 3-(p-hydroxyphenyl)-propano ...201222284459
electrochemical surface plasmon resonance measurement based on gold nanohole array fabricated by nanoimprinting technique.in this paper, we describe our development of an electrochemical surface plasmon resonance (ec-spr) measurement device based on a bottom-filled gold nanohole array. the polymer based gold nanohole array was fabricated with a uv nanoimprint technique and electron beam gold deposition. direct reflection mode measurement was used to monitor the spr dip in the reflection spectra. a cyclic voltammogram was also operated by using the standard three electrodes containing working electrode having a gold ...201222283116
obtention of plant peroxidase and its potential for the decolorization of the reactive dye remazol turquoise g 133%.peroxidases can be used in the decolorization process. there is a growing interest for new sources of this enzyme and for obtaining economically viable processes. in this work, a low-cost vegetable peroxidase extraction process is proposed; the resulting enzyme is characterized to determine its optimum ph, temperature, and stability conditions, and it is then applied in the decolorization of reactive dye remazol turquoise g 133%. the turnip peroxidase (tp) was utilized as an enzymatic source. th ...201222277225
sortase a-catalyzed site-specific coimmobilization on microparticles via streptavidin.a microparticle surface was designed by the unique method incorporating streptavidin-biotin affinity and sortase a (srta)-catalyzed transpeptidation. leucine-proline-glutamate-threonine-glycine-tagged streptavidin (stav-lpetg)was immobilized on the surface using streptavidin-biotin affinity, and ggggg-tagged red fluorescent protein (gly5-rfp) was conjugated with srta. biotinylated fluorescein isothiocyanate (biotin-fitc) was then bound to residual biotin-binding sites in stav-lpetg. the resultin ...201222276782
protein functionalized titania particle as a nanocarrier in a multiple signal antibody amplification strategy for ultrasensitive chemiluminescent immunoassay.a simple and sensitive method for amplified chemiluminescent immunoassay has been developed by using multiple signal antibodies functionalized titania nanoparticle as tracer. this nanocomposite was fabricated by sequentially conjugating bovine serum albumin and horseradish peroxidase-labeled antibody onto the surface of titania nanoparticles using glutaraldehyde as the linkage. after a sandwich immuno-binding process, the captured nanocomposite tracer greatly catalyzed the luminol chemiluminesce ...201222265572
evaluation of seven cosubstrates in the quantification of horseradish peroxidase enzyme by square wave voltammetry.the electrochemical detection for horseradish peroxidase-cosubstrate-h(2)o(2) systems was optimized. o-phenilendiamine, phenol, hydroquinone, pyrocatechol, p-chlorophenol, p-aminophenol and 3,3'-5,5'-tetramethylbenzidine were evaluated as cosubstrates of horseradish peroxidase (hrp) enzyme. therefore, the reaction time, the addition sequence of the substrates, the cosubstrate:h(2)o(2) ratio and the electrochemical techniques were elected by one-factor optimization assays while the buffer ph, the ...201222265528
ultrasensitive electrochemical immunosensor based on au nanoparticles dotted carbon nanotube-graphene composite and functionalized mesoporous materials.a facile and sensitive electrochemical immunosensor for detection of human chorionic gonadotrophin (hcg) was designed by using functionalized mesoporous nanoparticles as bionanolabels. to construct high-performance electrochemical immunosensor, au nanoparticles (aunps) dotted carbon nanotubes (mwcnts)-graphene composite was immobilized on the working electrode, which can increase the surface area to capture a large amount of primary antibodies (ab(1)) as well as improve the electronic transmissi ...201222265320
magnetic nanocomposite of anti-human igg/cooh-multiwalled carbon nanotubes/fe₃o₄ as a platform for electrochemical immunoassay.an electrochemical immunosensing method was developed based on a magnetic nanocomposite. the multiwalled carbon nanotubes (mwcnts) were treated with nitric acid to produce carboxyl groups at the open ends. then, fe₃o₄ nanoparticles were deposited on cooh-mwcnts by chemical coprecipitation of fe²⁺ and fe³⁺ salts in an alkaline solution. goat anti-human igg (anti-higg) was covalently attached to magnetic nanocomposite through amide bond formation between the carboxylic groups of mwcnts and the ami ...201222245258
electron transfer and electrocatalytics of cytochrome c and horseradish peroxidase on dna modified electrode.a bio-interphase composed of dna, cytochrome c (cyt c) and horseradish peroxidase (hrp) was developed by layer-by-layer assembling cyt c, dna and cyt c-hrp on biocompatible 11-mercaptoundecanoic acid--6-mercapto-1-hexanol modified gold electrode. the new bio-interphase was used as a model system to mimic the electron transfer and electrocatalytic performance of two proteins in living organisms. results showed that the electron transfer rate at bi-protein bio-interphase was faster than those at t ...201222243789
amplified detection of dna through the enzyme-free autonomous assembly of hemin/g-quadruplex dnazyme nanowires.an enzyme-free amplified detection platform is described using the horseradish peroxidase (hrp)-mimicking dnazyme as an amplifying label. two hairpin structures that include three-fourths and one-fourth of the hrp-mimicking dnazyme in caged, inactive configurations are used as functional elements for the amplified detection of the target dna. in the presence of the analyte dna, one of the hairpins is opened, and this triggers the autonomous cross-opening of the two hairpins using the strand disp ...201222242838
dna-programmed modular assembly of cyclic and linear nanoarrays for the synthesis of two-dimensional conducting polymers.nanometer-scale arrays of conducting polymers were prepared on scaffolds of self-assembling dna modules. a series of dna oligomers was prepared, each containing six 2,5-bis(2-thienyl)pyrrole (sns) monomer units linked covalently to n4 atoms of alternating cytosines placed between leading and trailing 12-nucleobase recognition sequences. these dna modules were encoded so the recognition sequences would uniquely associate through watson-crick assembly to form closed-cycle or linear arrays of align ...201222242713
ph-, sugar-, and temperature-sensitive electrochemical switch amplified by enzymatic reaction and controlled by logic gates based on semi-interpenetrating polymer networks.phenylboronic acid (pba) moieties are grafted onto the backbone of poly(acrylic acid) (paa), forming the paa-pba polyelectrolyte. the semi-interpenetrating polymer network (semi-ipn) films composed of paa-pba and poly(n,n-diethylacrylamide) (pdea) were then synthesized on electrode surface with entrapped horseradish peroxidase (hrp), designated as pdea-(paa-pba)-hrp. the films demonstrated reversible ph-, fructose-, and thermo-responsive on-off behavior toward electroactive probe k(3)fe(cn)(6) i ...201222239642
rational design of surface/interface chemistry for quantitative in vivo monitoring of brain chemistry.to understand the molecular basis of brain functions, researchers would like to be able to quantitatively monitor the levels of neurochemicals in the extracellular fluid in vivo. however, the chemical and physiological complexity of the central nervous system (cns) presents challenges for the development of these analytical methods. this account describes the rational design and careful construction of electrodes and nanoparticles with specific surface/interface chemistry for quantitative in viv ...201222236096
a new dual immunoassay for tumor markers based on chemiluminescence signal amplification by magnetic mesoporous silica and enzyme modified gold nanoparticles.a sensitive dual immunoassay was proposed for the determination of carcinoembryonic antigen (cea) and α-fetoprotein (afp) based on signal amplification. monoclonal antibodies immobilized on magnetic mesoporous silica particles (fe(3)o(4)/sio(2)) were prepared as the primary probe. horseradish peroxidase (hrp) labeled antibodies co-coated with hrp on gold nanoparticles (aunps) were used as the secondary probe to achieve signal amplification. hrp tags were retained in the flow cells after a sandwi ...201222232219
screening of postharvest agricultural wastes as alternative sources of peroxidases: characterization and kinetics of a novel peroxidase from lentil ( lens culinaris l.) stubble.aqueous crude extracts of a series of plant wastes (agricultural, wild plants, residues from sports activities (grass), ornamental residues (gardens)) from 17 different plant species representative of the typical biodiversity of the iberian peninsula were investigated as new sources of peroxidases (ec 1.11.1.7). of these, lentil (lens culinaris l.) stubble crude extract was seen to provide one of the highest specific peroxidase activities, catalyzing the oxidation of guaiacol in the presence of ...201222534011
a neuroanatomical correlate of sensorimotor recovery in response to repeated vaginocervical stimulation in rats.gentle probing against the cervix via the vagina (vaginocervical stimulation, vcs) increases tail flick latency (tfl) to radiant heat; greater force abolishes the tail flick response and other withdrawal responses. this effect occurs in spinal cord-transected rats and in intact rats. on the basis of our earlier finding that vcs releases vasoactive intestinal peptide (vip) into the spinal cord, and others' reports of neurotrophic effects of vip in vitro, we hypothesized that repeated vcs would st ...201222529817
fluid outflow in a large-animal model of posttraumatic syringomyelia.posttraumatic syringomyelia affects approximately 28% of spinal cord injury patients, and current treatments are often ineffective. the pathogenesis of this condition remains poorly understood. previous reports have focused on pathways and mechanisms of fluid inflow; however, disturbances of fluid outflow mechanisms and pathways may be important in syrinx formation and enlargement.201222513840
retinal compensatory changes after light damage in albino mice.to investigate the anatomic and functional changes triggered by light exposure in the albino mouse retina and compare them with those observed in the albino rat.201222509098
promoting immobilization and catalytic activity of horseradish peroxidase on mesoporous silica through template micelles.new concept on the promotion of immobilization and catalytic activity of enzyme on mesoporous silica through template micelles is proposed and realized in this paper. proper p123 templates are controllable retained in the as-synthesized sba-15, not only to anchor the horseradish peroxidase (hrp) guest, but also to establish the crowding-like microenvironment around the enzyme. the influence of retaining templates on the pore structure of sba-15, immobilization, and catalytic activity of hrp is s ...201222507401
a dynamic fed batch strategy for a pichia pastoris mixed feed system to increase process understanding.mixed substrate feeding strategies are frequently investigated to enhance the productivity of recombinant pichia pastoris processes. for this purpose, numerous fed batch experiments or time-consuming continuous cultivations are required to optimize control parameters such as the substrate mixing ratio and the applied methanol concentration. in this study, we decoupled the feeding of methanol and glycerol in a mixed substrate fed batch environment to gain process understanding for a recombinant p ...201222505140
enzyme-based ultrasensitive electrochemical biosensors.signal amplification in conventional enzyme-based biosensors is not high enough to achieve the ultrasensitive detection of biomolecules. in recent years, signal amplification has been improved by combining enzymatic reactions with redox cycling or employing multienzyme labels per detection probe. electrochemical-chemical redox cycling and electrochemical-chemical-chemical redox cycling allow ultrasensitive detection simply by including one or two more chemicals in a solution without the use of a ...201222503680
electric-field-directed self-assembly of active enzyme-nanoparticle structures.a method is presented for the electric-field-directed self-assembly of higher-order structures composed of alternating layers of biotin nanoparticles and streptavidin-/avidin-conjugated enzymes carried out on a microelectrode array device. enzymes included in the study were glucose oxidase (gox), horseradish peroxidase (hrp), and alkaline phosphatase (ap); all of which could be used to form a light-emitting microscale glucose sensor. directed assembly included fabricating multilayer structures w ...201222500078
a membrane-based elisa assay and electrochemical immunosensor for microcystin-lr in water samples.we describe within this paper the development of an affinity sensor for the detection of the cyanobacterial toxin microcystin-lr. the first stage of the work included acquiring and testing of the antibodies to this target. following the investigation, a heterogeneous direct competitive enzyme-linked immunosorbent assay (elisa) format for microcystin-lr detection was developed, achieving a detection limit, lld(80) = 0.022 μg l(-1). the system was then transferred to an affinity membrane sorbent-b ...201222493936
development of a near-infrared fluorescence elisa method using tyramide signal amplification.in this study, we applied tyramide signal amplification (tsa) to fluorescence enzyme-linked immunosorbent assay (elisa) employing horseradish peroxidase (hrp) as the detection enzyme. when used with a human epidermal growth factor elisa kit, the tsa method led to a >100-fold increase in fluorescence signal intensity in comparison to an unamplified method. it also showed wider dynamic range and better sensitivity compared to a conventional method using tetramethylbenzidine as the hrp substrate.201222490466
immobilization of peroxidase onto magnetite modified polyaniline.the present study describes the immobilization of horseradish peroxidase (hrp) on magnetite-modified polyaniline (panimg) activated with glutaraldehyde. after the optimization of the methodology, the immobilization of hrp on panimg produced the same yield (25%) obtained for panig with an efficiency of 100% (active protein). the optimum ph for immobilization was displaced by the effect of the partition of protons produced in the microenvironment by the magnetite. the tests of repeated use have sh ...201222489198
displacement immunoassay for the detection of ochratoxin a using ochratoxin b modified glass beads.we report here the development of a new assay for the detection of ochratoxin a (ota) based on the use of its dechlorinated analogue, ochratoxin b (otb), in a displacement immunoassay. otb was immobilised on controlled-pore glass beads followed by the binding of anti-ota antibody, with anti-igg antibody peroxidase conjugate used as a label. in this manner, an original bio-sensing material was obtained. upon incubation of this material with ota, the toxin competes with otb for the binding sites o ...201222331050
development of a solid-phase extraction coupling chemiluminescent enzyme immunoassay for determination of organophosphorus pesticides in environmental water samples.solid-phase extraction (spe) and direct competitive chemiluminescence enzyme immunoassay (dccl-eia) were combined for the detection of organophosphorus pesticides (ops) in environmental water samples. dccl-eia based on horseradish peroxidase labeled with a broad-specificity monoclonal antibody against ops was developed, and the effects of several physicochemical parameters on dccl-eia performance were studied. spe was used for the pretreatment of water samples to remove interfering substances an ...201222329773
highly sensitive chemiluminescent analysis of residual bovine serum albumin (bsa) based on a pair of specific monoclonal antibodies and peroxyoxalate-glyoxaline-phppa dimer chemiluminescent system in vaccines.enzyme-linked immunosorbent assay (elisa), horseradish peroxidase (hrp)-catalyzed fluorescent reaction, and oxalate chemiluminescence analysis have been combined to develop a highly sensitive, simple, and rapid method for analysis of bovine serum albumin (bsa) based on a pair of specific monoclonal antibodies in vaccines. a typical "sandwich type" immunoassay was used. reaction of 3-(4-hydroxyphenyl propionate) (phppa) with hydrogen peroxide-urea, catalyzed by hrp, produced fluorescence of 3-(4- ...201222328250
chemiluminescence imaging immunoassay of multiple tumor markers for cancer screening.a sensitive chemiluminescence (cl) imaging immunoassay method for detection of multiple tumor markers with high throughput, easy operation, and low cost was developed. the immunosensor array was prepared by covalently immobilizing capture antibodies on corresponding sensing sites on a silanized disposable glass chip. gold nanoparticle-based bioconjugates with a high molar ratio of horseradish peroxidase (hrp) to detection antibodies were used for signal amplification. under a sandwich immunoassa ...201222320247
neuroprotective effects of testosterone on motoneuron and muscle morphology following spinal cord injury.treatment with testosterone is neuroprotective/neurotherapeutic after a variety of motoneuron injuries. here we assessed whether testosterone might have similar beneficial effects after spinal cord injury (sci). young adult female rats received either sham or t9 spinal cord contusion injuries and were implanted with blank or testosterone-filled silastic capsules. four weeks later, motoneurons innervating the vastus lateralis muscle of the quadriceps were labeled with cholera toxin-conjugated hor ...201222314886
dna template-assisted modulation of horseradish peroxidase activity.the precise alignment of dna molecules by watson-crick base-pairing combined with its polymeric characteristics have allowed dna to be used as a template or scaffold for assembling materials. in this work, we investigate the role of calf-thymus dna as a template for enhancing the horseradish peroxidase (hrp)-mediated oxidation of phenol and phenolic derivatives. the hrp-catalyzed oxidation of phenol into polyphenolic products and in presence of 4-aminoantipyrine into quinoneimine dye complexes i ...201222305796
triplex signal amplification for electrochemical dna biosensing by coupling probe-gold nanoparticles-graphene modified electrode with enzyme functionalized carbon sphere as tracer.an ultrasensitive electrochemical dna biosensor was constructed by assembling probe labeled gold nanoparticles (ssdna-aunp) on electrochemically reduced graphene oxide (ergo) modified electrode with thiol group tagged (gt) dna strand (d(gt)(29)sh) and coupling with horseradish peroxidase (hrp) functionalized carbon sphere (cns) as tracer. the heteronanostructure formed on the biosensor surface appeared relatively good conductor for accelerating the electron transfer, while the hrp tagged cns pro ...201222305443
chemical kinetics and interactions involved in horseradish peroxidase-mediated oxidative polymerization of phenolic compounds.the primary objective of this research was to evaluate various factors that affect the reaction rate of oxidative coupling (oxc) reaction of phenolic estrogens catalyzed by horseradish peroxidase (hrp). kinetic parameters were obtained for the conversion of phenol as well as natural and synthetic estrogens estrone (e(1)), 17β-estradiol (e(2)), estriol (e(3)), and 17α-ethinylestradiol (ee(2)). molecular orbital theory and autodock software were employed to analyze chemical properties and substrat ...201222305176
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