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randomised clinical trial: the effects of perioperative probiotic treatment on barrier function and post-operative infectious complications in colorectal cancer surgery - a double-blind study.infection following abdominal operation remains a major factor affecting the morbidity of patients after surgery.201121083585
horseradish peroxidase-screen printed biosensors for determination of ochratoxin a.this work summarizes the manufacturing procedure of horseradish peroxidase (hrp) based biosensors for the determination of the mycotoxin ochratoxin a (ota). the biosensors have been fabricated using the single technology of screen-printing. that is to say, an hrp containing ink has been directly screen-printed onto carbon electrodes, which offers a higher rapidity and simplicity in the manufacturing process of biosensors for ota determination. the formal redox potential of the fe(iii/ii) moiety ...201121296204
hydrogen peroxide sensing with horseradish peroxidase-modified polymer single conical nanochannels.inspired from the funtioning and responsiveness of biological ion channels, researchers attempt to develop biosensing systems based on polymer and solid-state nanochannels. the applicability of these nanochannels for detection/sensing of any foreign analyte in the surrounding environment depends critically on the surface characteristics of the inner walls. attaching recognition sites to the channel walls leads to the preparation of sensors targeted at a specific molecule. there are many nanochan ...201121294554
phosphate buffer effects on thermal stability and h2o2-resistance of horseradish peroxidase.horseradish peroxidase (hrp) has attracted intense research interest due to its potential applications in biotechnological fields. however, inadequate stability under prevalent conditions such as elevated temperatures and h(2)o(2) exposure, has limited its industrial application. in this study, stability of hrp was investigated in the presence of different buffer systems (potassium phosphate and tris-hcl) and additives. it was shown that the concentration of phosphate buffer severely affects enz ...201121291907
oligonucleotide probes applied for sensitive enzyme-amplified electrochemical assay of mercury(ii) ions.we developed a novel electrochemical sensor for hg(2+) detection using two mercury-specific oligonucleotide probes and streptavidin-horseradish peroxidase (hrp) enzymatic signal amplification. the two mercury-specific oligonucleotide probes comprised a thiolated capture probe and a biotinated signal probe. the thiolated capture probe was immobilized on a gold electrode. in the presence of hg(2+), the thymine-hg(2+)-thymine (t-hg(2+)-t) interaction between the mismatched t-t base pairs directed t ...201121288711
rachiplusia nu larva as a biofactory to achieve high level expression of horseradish peroxidase.a process based on orally-infected rachiplusia nu larvae as biological factories for expression and one-step purification of horseradish peroxidase isozyme c (hrp-c) is described. the process allows obtaining high levels of pure hrp-c by membrane chromatography purification. the introduction of the partial polyhedrin homology sequence element in the target gene increased hrp-c expression level by 2.8-fold whereas it increased 1.8-fold when the larvae were reared at 27 °c instead of at 24 °c, sum ...201121287234
signal-enhancing thermosensitive liposomes for highly sensitive immunosensor development.liposomes are potential candidates as nanovesicles for the development of detection systems with improved sensitivity and detection limits, due to their capacity to encapsulate diverse types of signal enhancing molecules. an amperometric immunosensor exploiting enzyme encapsulating thermosensitive liposomes for the ultrasensitive detection of carcinoembryonic antigen (cea) is reported. five different bioconjugation methods to link an anti-cea antibody to horseradish peroxidase (hrp) encapsulatin ...201121155541
a novel h2o2 sensor based on the enzymatically induced deposition of polyaniline at a horseradish peroxide/aligned single-wall carbon nanotubes modified au electrode.a novel h(2)o(2) sensor based on enzymatically induced deposition of electroactive polyaniline (pani) at a horseradish peroxide (hrp)/aligned single-wall carbon nanotubes (swcnts) modified au electrode is fabricated, and its electrochemical behaviors are investigated. electrochemical impedance spectroscopy of the sensor confirmed the formation of pani on swcnts through the hrp catalytic reaction. cyclic voltammograms of pani/hrp/swcnts modified au electrodes showed a pair of well-defined redox p ...201121152626
development of porous alginate-based scaffolds covalently cross-linked through a peroxidase-catalyzed reaction.porous scaffolds are important in tissue engineering. we developed porous scaffolds from the hydrogels of an alginate derivative bearing phenolic hydroxyl groups. the hydrogels were prepared using horseradish peroxidase (hrp) to catalyze the cross-linking between the phenolic hydroxyl groups. a porous structure with a pore size of approx. 200 μm was developed through simultaneous water-extraction and ionic cross-linking by calcium ions by soaking frozen hydrogels in the mixture of ethanol and ca ...201121144141
vertical and horizontal transmission of tilapia larvae encephalitis virus: the bad and the ugly.impairment of innate immunity in tilapia larvae after vertical and horizontal infection with the newly characterized tilapia larvae encephalitis virus (tlev) was accessed by evaluation of cell-mediated reactive oxygen species (ros) production in affected fish with the use of horseradish peroxidase-amplified luminol-dependent chemiluminescence assay. the priming in-vivo infection with tlev resulted in downregulation of ros response in both vertically- and horizontally-infected fish; this suppress ...201121131016
a novel and efficient oxidative functionalization of lignin by layer-by-layer immobilised horseradish peroxidase.horseradish peroxidase (hrp) was chemically immobilised onto alumina particles and coated by polyelectrolytes layers, using the layer-by-layer technique. the reactivity of the immobilised enzyme was studied in the oxidative functionalisation of softwood milled wood and residual kraft lignins and found higher than the free enzyme. in order to investigate the chemical modifications in the lignin structure, quantitative (31)p nmr was used. the immobilised hrp showed a higher reactivity with respect ...201121130661
amperometric biosensors based on alumina nanoparticles-chitosan-horseradish peroxidase nanobiocomposites for the determination of phenolic compounds.a horseradish peroxidase (hrp) biosensor based on alumina (al(2)o(3)) nanoparticles-chitosan (chit) nanocomposites was developed for the detection of phenolic compounds. uv-vis spectra and fourier transform infrared spectra showed that hrp retained its original structure on the al(2)o(3)/chit film. the surface morphologies of the composite films were characterized by scanning electron microscopy. cyclic voltammetry and amperometry were used to study the proposed electrochemical biosensor. optimi ...201121127796
photoresponsive dna-cross-linked hydrogels for controllable release and cancer therapy.we have developed a photoresponsive dna-cross-linked hydrogel that can be photoregulated by two wavelengths with a reversible sol-gel conversion. this photoinduced conversion can be further utilized for precisely controllable encapsulation and release of multiple loads. specifically, photosensitive azobenzene moieties are incorporated into dna strands as cross-linkers, such that their hybridization to complementary dnas (cdnas) responds differently to different wavelengths of light. on the basis ...201121126095
enhanced stability and decolorization of coomassie brilliant blue r-250 by dextran aldehyde-modified horseradish peroxidase.horseradish peroxidase (ec 1.11.1.7) was chemically modified by periodate-activated dextran. the activities of free and modified enzyme against organic-aqueous interface and some chemicals were determined. modified hrp remained fully active in the presence of organic solvent for 4 h. however, the unmodified enzyme lost 50% of its activity within the first 2 h. the effects of possible inhibitors on enzyme activity were investigated. in addition, coomassie brilliant blue r-250 was efficiently deco ...201121117874
oxidative biodegradation of single- and multi-walled carbon nanotubes.in this study we compare the biodegradation of both single-walled (swcnts) and multi-walled carbon nanotubes (mwcnts) using two different oxidative conditions. in particular, we demonstrate that oxidized multi-walled carbon nanotubes are highly degraded, although not to completeness when treated with horseradish peroxidase (hrp) in the presence of hydrogen peroxide.201121116547
horseradish peroxidase as a catalyst for atom transfer radical polymerization.the hemoprotein horseradish peroxidase (hrp) catalyzes the polymerization of n-isopropylacrylamide with an alkyl bromide initiator under conditions of activators regenerated by electron transfer atom transfer radical polymerization (arget atrp) in the absence of any peroxide. this is a novel activity of hrp, which we propose to name atrpase activity. bromine-terminated polymers with polydispersity indices (pdis) as low as 1.44 are obtained. the polymerization follows first order kinetics, but th ...201121842510
direct quantitation of peptide-mediated protein transport across a droplet-interface bilayer.we introduce a new method for monitoring and quantitating the transport of materials across a model cell membrane. as a proof-of-concept, the cell-penetrating peptide, pep-1, was used to carry horseradish peroxidase (hrp) across droplet-interface bilayers (dibs). two submicroliter, lipid-encased aqueous droplets form a membrane at the contacting interface, through which enzyme-peptide complexes pass during transport. following transport, the droplets are separated and the captured enzymes are as ...201121838329
fabrication of robust multilayer films by triggering the coupling reaction between phenol and primary amine groups with visible light irradiation.we prepared robust cross-linked (x-linked) multilayer films under visible light irradiation with the catalysis of a ru(ii) complex. the x-linking is achieved by the coupling reaction between phenol group and primary amine group within the self-assembled multilayer films that were prepared beforehand. three kinds of polymers, i.e., poly(4-vinylphenol), poly(allylamine) and poly(ethyleneimine), were selected as the model system to illustrate the concept of this strategy. upon visible light irradia ...201121837325
effect of substrate (zno) morphology on enzyme immobilization and its catalytic activity.in this study, zinc oxide (zno) nanocrystals with different morphologies were synthesized and used as substrates for enzyme immobilization. the effects of morphology of zno nanocrystals on enzyme immobilization and their catalytic activities were investigated. the zno nanocrystals were prepared through a hydrothermal procedure using tetramethylammonium hydroxide as a mineralizing agent. the control on the morphology of zno nanocrystals was achieved by varying the ratio of ch3oh to h2o, which wer ...201121752255
light regulation of peroxidase activity by spiropyran functionalized carbon nanotubes used for label-free colorimetric detection of lysozyme.spiropyran dye-modified multi-walled carbon nanotubes have been synthesized and used to regulate horseradish peroxidase activity by light irradiation. this design has been developed for a label-free colorimetric assay of lysozyme with a direct detection limit of 30 nm.201121748199
uniform polymer-protein conjugate by aqueous aget atrp using protein as a macroinitiator.in situ aqueous activators generated by electron transfer for atom transfer radical polymerization (aget atrp) in air, using an enzyme as a macroinitiator, has been proposed to prepare uniform polymer-protein conjugates with improved stability under adverse conditions. in the first step, an initiator, 2-bromoisobutyryl bromide (bib), was grafted onto the protein surface by reaction with the amino groups. the second step was in situ aget atrp polymerization in air using cubr(2)/1,1,4,7,7-pentamet ...201121277397
toxic effect of terbium ion on horseradish cell.the toxic effect of terbium (iii) ion on the horseradish cell was investigated by scanning electron microscopy, gas chromatography, and standard biochemical methods. it was found that the activity of horseradish peroxidase in the horseradish treated with 0.2 mm terbium (iii) ion decreased and led to the excessive accumulation of free radicals compared with that in the control horseradish. the excessive free radicals could oxidize unsaturated fatty acids in the horseradish cell and then increase ...201121271297
horseradish peroxidase functionalized fluorescent gold nanoclusters for hydrogen peroxide sensing.the fluorescence of metal nanoclusters provides an amusing optic feature to be applied in various fields. however, rational design of dual functional fluorescent metal nanoclusters directed by active enzyme with targeted application remains little explored. in this work, we report a new strategy to construct enzyme functionalized fluorescent gold nanoclusters via a biomineralization process for the detection of hydrogen peroxide. horseradish peroxidase (hrp) was used as a model functional templa ...201121261275
an electrochemical competitive biosensor for ochratoxin a based on a dna biotinylated aptamer.ochratoxin a (ota) is one of the most important mycotoxin contaminants of foods, particularly cereals and cereal products, with strict low regulatory levels (of ppb) in many countries worldwide. an electrochemical competitive aptamer-based biosensor for ota is described. paramagnetic microparticle beads (mbs) were functionalized with an aptamer specific to ota, and were allowed to compete with a solution of the mycotoxin conjugated to the enzyme horseradish peroxidase (ota-hrp) and free ota. aft ...201121256729
a quantitative chemiluminescent assay for analysis of peroxide-based explosives.a quantitative chemiluminescent method, enabling indirect identification of the peroxide-based explosives tatp (triacetone triperoxide) and hmtd (hexamethylene triperoxide diamine) has been developed. treatment of these compounds with acidic solutions produced peroxides, which were transformed into radical derivatives by horseradish peroxidase (hrp) and then quantified by measuring the light emitted during their oxidation of luminol. the method was first developed in the microplate format and la ...201121249343
the fidelity of spin trapping with dmpo in biological systems.unlike direct esr, spin trap methodology depends on the absolute fidelity of the spin trap reaction. two alternative reactions of 5,5-dimethyl-1-pyrroline n-oxide (dmpo) leading to radical adduct artifacts have been discovered and investigated: inverted spin trapping and the forrester-hepburn nucleophilic mechanism. these two alternate pathways to radical adducts are a combination of one-electron oxidation and nucleophilic addition, in either order. in biological systems, serious artifacts have ...201121246623
additive effect of dextrans on the stability of horseradish peroxidase.the influence of various concentration (10, 20, and 30% w/v) of different molar weighted dextrans as additives on the stability of hrp has been studied in aqueous medium. native hrp preparations were formulated with different additives for storage stabilization and better performance at high temperature and ph. the results obtained show a stabilizing effect in the presence of an additive (75 kda dextran). the enzyme with 75 kda dextran (in concentration 10% w/v) showed the highest thermal resist ...201121243417
multiplexed sensing based on brownian relaxation of magnetic nanoparticles using a compact ac susceptometer.a novel multiplexed sensing scheme based on the measurement of the magnetic susceptibility of the affinity captured target molecules on magnetic nanoparticles in liquid suspension is proposed. the ac magnetic susceptibility provides a measurement of brownian relaxation behavior of biomolecules bound to magnetic nanoparticles (mnps) that is related to its hydrodynamic size. a room temperature, compact ac susceptometer is designed and developed to measure complex ac magnetic susceptibility of such ...201121242618
covalent immobilization of horseradish peroxidase via click chemistry and its direct electrochemistry.a simple and versatile approach for covalent immobilization of redox protein on solid surface via self-assembled technique and click chemistry is reported. the alkynyl-terminated monolayers are obtained by self-assembled technique, then, azido-horseradish peroxidase (azido-hrp) was covalent immobilized onto the formed monolayers by click reaction. the modified process is characterized by reflection absorption infrared spectroscopy (rair), surface-enhanced raman scattering spectroscopy (sers) and ...201121238725
gold nanoparticles based chemiluminescent resonance energy transfer for immunoassay of alpha fetoprotein cancer marker.in this paper, we report a new strategy of chemiluminescence resonance energy transfer (cret) by using gold nanoparticles (aunps) as efficient long-range energy acceptor in sandwich immunoassays. in the design of cret system, we chose the highly sensitive chemiluminescence (cl) reaction of luminol and hydrogen peroxide catalysed by horseradish peroxidase (hrp) because the cl spectrum of luminol (λ(max) 425 nm) partially overlaps with the visible absorption bands of aunps. on the basis of cret st ...201121237316
detection and comparison of protein-dna interactions using dna-bind plate and horseradish peroxidase-based colorimetric assay.we describe a procedure for detection and comparison of protein-dna interactions using dna-bind plate and horseradish peroxidase (hrp)-based colorimetric assay. amino-modified oligonucleotide was covalently immobilized on the surface of dna-bind plate. after the complementary oligonucleotide was annealed, the plate was incubated with protein to allow sequence-specific dna binding. primary antibody and hrp-labeled secondary antibody were then employed, and colorimetric assay was conducted before ...201121237130
determination of sphingomyelinase-d activity of loxosceles venoms in sphingomyelin/cholesterol liposomes containing horseradish peroxidase.based on degradation of sphingomyelin/cholesterol liposomes containing entrapped horseradish peroxidase, we evaluated the sphingomyelinase-d (smase-d) activity of scorpion, spider and snake venoms by monitoring spectrophotometrically the product of oxidation of hrp released. the results indicate that loxosceles crude venoms (loxosceles intermedia, loxosceles laeta, loxosceles gaucho and loxosceles similis) displayed smase-d activity in a concentration-dependent manner. furthermore, this activity ...201121236288
in situ molecular detection of ischemic cells by enhanced protein direct electron transfer on a unique horseradish peroxidase-au nanoparticles-polyaniline nanowires biofilm.to overcome shortcomings of the ex situ approaches, in situ detection using h(2)o(2) molecules to diagnose ischemia through enhanced protein direct electron transfer on a unique horseradish peroxidase-au nanoparticles-polyaniline nanowires biofilm is demonstrated and it is discovered that the extracellular h(2)o(2) molecule released per ischemic cell is 2.7-times of that of a normal cell.201121234479
fluorescent derivatization of xanthurenic acid and nicotinic acid with horseradish peroxidase in the presence of excess hydrogen peroxide.the fluorescent derivatization of tryptophan metabolites (xanthurenic acid, nicotinic acid, picolinic acid, and 3-hydroxyanthranilic acid) by the catalytic activity of horseradish peroxidase (hrp) was investigated in the presence of excess h(2)o(2). non-fluorescent xanthurenic acid (xa) and nicotinic acid (na) were converted into a fluorescent compound with maximum excitation and emission wavelengths at 325 and 425 nm, and 318 and 380 nm, respectively. this fluorescent derivatization was develop ...201121233570
the enzyme-mediated activation of radical source reaction: a new approach to identify partners of a given molecule in membrane microdomains.important biological events associated with plasma membranes, such as signal transduction, cell adhesion, and protein trafficking, are mediated through the membrane microdomains. however, it is difficult to assess the issue of how they assemble under physiological conditions. we developed a new approach to identify partners of a given molecule on the cell surface in living cells. the important feature of this system, termed as enzyme-mediated activation of radical source, is that activation of c ...201121214558
sensitive electrochemical immunosensor for cancer biomarker with signal enhancement based on nitrodopamine-functionalized iron oxide nanoparticles.a novel electrochemical immunosensor for sensitive detection of cancer biomarker prostate specific antigen (psa) based on nitrodopamine (nda) functionalized iron oxide nanoparticles (nda-fe(3)o(4)) is described. nda-fe(3)o(4) was used both for the immobilization of primary anti-psa antibody (ab(1)) and as secondary anti-psa antibody (ab(2)) label. for the preparation of the label, mediator thionine (th) was first conjugated onto nda-fe(3)o(4) based on the amino groups of nda, and then the amino ...201121195601
[development of primary visual cortex connections with the motion processing center: the role of visual environment].development of axonal connections between cat primary visual area 17 and visual motion processing center was studied to investigate cortico-cortical connection plasticity in ontogenesis as affected by an experimental modification of visual environment (flickering light stimulation). by using a retrograde axonal labeling by horseradish peroxidase, a distribution of initial neurons in area 17 that send afferent projections to pmls (posterior medial part of lateral suprasylvian sulcus) was analyzed ...201122506347
facile synthesis of fe(3)o(4)@al(2)o(3) core-shell nanoparticles and their application to the highly specific capture of heme proteins for direct electrochemistry.in this study, magnetic core-shell fe(3)o(4)@al(2)o(3) nanoparticles (nps) attached to the surface of a magnetic glassy carbon electrode (mgce) were used as a functional interface to immobilize several heme proteins including hemoglobin (hb), myoglobin (mb) and horseradish peroxidase (hrp) for fabricating protein/fe(3)o(4)@al(2)o(3) film. transmission electron microscope, uv-vis spectroscopy, electrochemical impedance spectroscopy, and cyclic voltammetry were used to characterize the films. with ...201121185712
botanical micelle and its application for direct electrochemical biosensor.this paper is concerned about the entrapment of horseradish peroxidase (hrp) within botanical inositol hexakisphosphoric (ip(6)) micelles for the preparation of enzyme biosensor. the good affinity of ip(6) micelles with the enzyme provides naturally biocompatible microenvironment for the enzyme immobilization, achieving the direct electron transfer between hrp and electrode surface. the resulting biosensor to h(2)o(2) detection exhibits a low detection limit of 0.1 μmol l(-1) (s/n = 3), a quick ...201121183331
a novel path for rapid transverse communication of vestibular signals in turtle cerebellum.voltage-sensitive dye activity within the thin, unfoliated turtle cerebellar cortex (cb) was recorded in vitro during eighth cranial nerve (nviii) stimulation. short latency responses were localized to the middle of the lateral edges of both ipsilateral and contralateral cb [vestibulocerebellum (vcb)]. even with a severed contralateral cb peduncle, stimulation of the nviii ipsilateral to the intact peduncle evoked contralateral vcb responses with a mean latency of only 0.25 ms after the ipsilate ...201121178000
design of a sandwich-mode amperometric biosensor for detection of pml/rarα fusion gene using locked nucleic acids on gold electrode.in this study, a novel dna electrochemical probe (locked nucleic acid, lna) was designed and involved in constructing an electrochemical dna biosensor for detection of promyelocytic leukemia/retinoic acid receptor alpha (pml/rarα) fusion gene in acute promyelocytic leukemia for the first time. this biosensor was based on a 'sandwich' sensing mode, which involved a pair of lna probes (capture probe immobilized at electrode surface and biotinyl reporter probe as an affinity tag for streptavidin-ho ...201121177095
electrochemical detection of extracellular hydrogen peroxide released from raw 264.7 murine macrophage cells based on horseradish peroxidase-hydroxyapatite nanohybrids.a new method developed for the reliable determination of extracellular and intracellular h(2)o(2) is very useful for gaining a full understanding of the role that h(2)o(2) plays in pathology and physiology, and the relationship between h(2)o(2) and environmental stresses and lipid peroxidation. this work developed and validated an electrochemical approach for the determination of extracellular h(2)o(2) released from raw 264.7 murine macrophage cells. this approach is based on the electrocatalyti ...201121170446
enzymatic degradation of a2e, a retinal pigment epithelial lipofuscin bisretinoid.some forms of blinding macular disease are associated with excessive accumulation of bisretinoid lipofuscin in retinal pigment epithelial (rpe) cells of the eye. this material is refractory to lysosomal enzyme degradation. in addition to gene and drug-based therapies, treatments that reverse the accumulation of bisretinoid would be beneficial. thus, we have examined the feasibility of degrading the bisretinoids by delivery of exogenous enzyme. as proof of principle we report that horseradish per ...201121166406
proof of principle for the synthesis of hydroxy-aryl esters of glycosidic polyols and non-reducing oligosaccharides with subsequent enzymatic coupling to a tyrosine-containing tripeptide.to enable enzymatic coupling of saccharides to proteins, several di- and trisaccharides were hydroxy-arylated using anhydrous transesterification with methyl 3-(4-hydroxyphenyl)propionate, catalyzed by potassium carbonate. this transesterification resulted in the attachment of up to 3 hydroxy-aryl units per oligosaccharide molecule, with the monosubstituted product being by far the most abundant. the alkaline reaction conditions, however, resulted in a partial breakdown of reducing sugars. this ...201121486666
a peroxidase-based method for the determination of dopamine, adrenaline, and α-methyldopa in the presence of thyroid hormones in pharmaceutical forms.the analytical properties of two commercial plant peroxidases isolated from horseradish roots and soybean hulls in the catalysis of the transformation of some catecholamines were demonstrated in the absence and presence of thyroid hormones (l-thyroxine and 3,3',5'-iodothyronine). for the first time the reactions of dopamine, adrenaline, and α-methyldopa oxidation with h(2)o(2) catalysed by horseradish peroxidase with the addition of l-thyroxine as the amplification agent were studied and propose ...201121482272
electrochemical biosensor with ph regulation of cnts/hrp multilayer for phenols.an amperometric horseradish peroxidase (hrp) biosensor based on multilayer films containing carbon nanotubes (cnts) and hrp was developed. with the ph regulation of the dispersion solution of cnts, the sensitivity of the hrp multilayer film biosensor is tunable by the control of the dissociation of cnts. the successful formation of multilayers was confirmed by uv-visible spectroscopy. the features of multilayers were characterized by sem and electrochemical impedance spectrum (eis). the performa ...201121478618
carbon-felt-based bioelectrocatalytic flow-detectors: optimization of the adsorption conditions of horseradish peroxidase and thionine onto carbon-felt for highly sensitive amperometric determination of h2o2.horseradish peroxidase (hrp) and thionine (th) were co-adsorbed onto a porous carbon-felt (cf) from a mixed solution of hrp and th to fabricate a cf-based bioelectrocatalytic flow-detector for h(2)o(2). the resulting hrp and th co-adsorbed cf (hrp/th-cf) was successfully used as a working electrode unit of a highly sensitive amperometric flow-h(2)o(2)-biosensor. differing from the ordinary mediator-based hrp biosensors, which detect mediated currents (i.e., the reduction current of the oxidized ...201121478616
a glucose sensor fabricated by piezoelectric inkjet printing of conducting polymers and bienzymes.piezoelectric inkjet printing of polymers and proteins holds great promise for fabrication of miniaturized bioelectronic devices, such as biochips and biosensors. in this study, a bienzymatic glucose biosensor prototype based on poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonic acid) (pedot-pss), glucose oxidase (god), and horseradish peroxidase (hrp) was fabricated by a piezoelectric inkjet printer. an aqueous bioelectrical ink containing pedot-pss, god, and hrp was prepared and printed on ...201121478612
glutamate reduces experimental intestinal hyperpermeability and facilitates glutamine support of gut integrity.to assess whether glutamate plays a similar role to glutamine in preserving gut wall integrity.201121472123
vesicular mixed gemini-sds-hemin-imidazole complex as a peroxidase-like nano artificial enzyme.a biomimetic was designed for the construction of a new efficient peroxidase-like nano artificial enzyme with a heme-imidazole component complexed with gemini 12-2-12/sds supramolecules. the presence of a simple surfactant mixture (sds/gemini 12-2-12 at a particular concentration) provided an apoprotein-like hydrophobic pocket for the heme-imidazole moiety, which produced a peroxidase active site containing positive and negative charges distributed on the colloidal surface. vesicular structures ...201121466180
signal amplification of streptavidin-horseradish peroxidase functionalized carbon nanotubes for amperometric detection of attomolar dna.a novel biosensing strategy for selective electrochemical detection of dna down to the attomolar level with a linear range of 5 orders of magnitude was developed by the specific recognitions of target dna and streptavidin to biotin labelled molecular beacon and signal amplification of streptavidin-horseradish peroxidase functionalized carbon nanotubes.201121461429
magnetic mesoporous organic-inorganic nico2o4 hybrid nanomaterials for electrochemical immunosensors.this study demonstrates a facile and feasible strategy toward the development of advanced electrochemical immunosensors based on chemically functionalized magnetic mesoporous organic-inorganic hybrid nanomaterials, and the preparation, characterization, and measurement of relevant properties of the immunosensor for detection of carcinoembryonic antigen (cea, as a model analyte) in clinical immunoassays. the as-prepared nanomaterials composed of a magnetic mesoporous nico(2)o(4) nanosheet, an int ...201121446771
a sensitive and selective direct competitive enzyme-linked immunosorbent assay for fast detection of sudan i in food samples.sudan i, a synthetic azo dye, is considered to be a genotoxic carcinogen and is prohibited in foodstuffs for any purpose at any level worldwide. in this study, a sensitive and specific direct competitive enzyme-linked immunosorbent assay (dc-elisa) for fast detection of sudan i in food samples was developed for the first time. the monoclonal antibody against sudan i was used as capture protein, while horseradish peroxidase labeled sudan i conjugate prepared by the periodate method via ovalbumin ...201121445880
plasmon-enhanced colorimetric elisa with single molecule sensitivity.robust but ultrasensitive biosensors with a capability of detecting low abundance biomarkers could revolutionize clinical diagnostics and enable early detection of cancer, neurological diseases, and infections. we utilized a combination of localized surface plasmon resonance (lspr) refractive index sensing and the well-known enzyme-linked immunosorbent assay to develop a simple colorimetric biosensing methodology with single molecule sensitivity. the technique is based on spectral imaging of a l ...201121428275
biomolecular conjugation inside synthetic polymer nanopores via glycoprotein-lectin interactions.we demonstrate the supramolecular bioconjugation of concanavalin a (con a) protein with glycoenzyme horseradish peroxidase (hrp) inside single nanopores, fabricated in heavy ion tracked polymer membranes. firstly, the hrp-enzyme was covalently immobilized on the inner wall of the pores using carbodiimide coupling chemistry. the immobilized hrp-enzyme molecules bear sugar (mannose) groups available for the binding of con a protein. secondly, the bioconjugation of con a on the pore wall was achiev ...201121423941
anisotropic magnetic porous assemblies of oxide nanoparticles interconnected via silica bridges for catalytic application.we report the microfluidic chip-based assembly of colloidal silanol-functionalized silica nanoparticles using monodisperse water-in-oil droplets as templates. the nanoparticles are linked via silica bridges, thereby forming superstructures that range from doublets to porous spherical or rod-like micro-objects. adding magnetite nanoparticles to the colloid generates micro-objects that can be magnetically manipulated. we functionalized such magnetic porous assemblies with horseradish peroxidase an ...201121417232
sensitive immunosensor for benzo[a]pyrene detection based on dual amplification strategy of pamam dendrimer and amino-modified methylene blue/sio₂ core-shell nanoparticles.a novel electrochemical immunosensor for sensitive detection of benzo[a]pyrene (bap) is constructed using poly(amido amine) (pamam) dendrimer and functionalized methylene blue/sio2 core-shell nanoparticle (mb/sio2) loaded with horseradish peroxidase (hrp) and hrp-secondary antibody (hrp-ab2). greatly enhanced sensitivity for bap analysis is based on a dual signal amplification strategy. firstly, the gold electrode (ge) was amino-functioned by electropolymerization of a novel compound, 2-amino-5, ...201121414770
solid-solid interface adsorption of proteins and enzymes in nanophase-separated amphiphilic conetworks.amphiphilic polymer conetworks (apcns) are materials with a very large interface between their hydrophilic and hydrophobic phases due to their nanophase-separated morphologies. proteins were found to enrich in apcns by up to 2 orders of magnitude when incubated in aqueous protein solutions, raising the question of the driving force of protein uptake into apcns. the loading of poly(2-hydroxyethyl acrylate)-linked by-poly(dimethylsiloxane) (phea-l-pdms) with heme proteins (myoglobin, horseradish p ...201121413720
fluorescence-tagged monolignols: synthesis, and application to studying in vitro lignification.fluorescence-tagged coniferyl alcohols, coniferyl alcohol γ-coupled by ethylenediamine spacers to dimethylaminocoumarin or nitrobenzofuran fluorophores, were tested as photoprobes to study the oxidase-mediated polymerization of monolignols. the fluorescent coniferyl alcohol derivatives readily underwent peroxidase-catalyzed in vitro copolymerization with coniferyl alcohol to yield fluorescent dehydrogenation polymers, the backbone polymers of which were structurally indistinguishable from polyme ...201121410250
rapid immobilization of enzymes onto solid supports by ultrasound waves.herein, we describe a non-conventional method for immobilization of enzymes onto different solid surfaces using ultrasound as a source of energy. when horseradish peroxidase (hrp) was taken on the surface of an activated support and allowed to float on a sonicator bath operating at a frequency of 40 khz, it readily started binding itself to the surface. maximum binding was observed in 10 min whereas a control experiment carried out similarly without ultrasound waves showed insignificant immobili ...201121401318
integrated electrokinetic magnetic bead-based electrochemical immunoassay on microfluidic chips for reliable control of permitted levels of zearalenone in infant foods.microfluidic technology has now become a novel sensing platform where different analytical steps, biological recognition materials and suitable transducers can be cleverly integrated yielding a new sensor generation. a novel "lab-on-a-chip" strategy integrating an electrokinetic magnetic bead-based electrochemical immunoassay on a microfluidic chip for reliable control of permitted levels of zearalenone in infant foods is proposed. the strategy implies the creative use of the simple channel layo ...201121394379
highly sensitive electrochemical label-free aptasensor based on dual electrocatalytic amplification of pt-aunps and hrp.in this work, a label-free electrochemical aptamer-based sensor (aptasensor) was constructed on account of the direct immobilization of redox probes on an electrode surface. for this proposed aptasensor, a gold nanoparticles (aunps)-coated electrode was firstly modified with redox probes-nickel hexacyanoferrates nanoparticles (nihcfnps) through chemisorption and electrostatic adsorption. then, platinum-gold alloy nanoparticles (pt-aunps) and horseradish peroxidase (hrp) were respectively assembl ...201121380419
signal amplification for dna detection based on the hrp-functionalized fe3o4 nanoparticles.an electrochemical approach for the sensitive detection of sequence-specific dna has been developed. horseradish peroxidase (hrp) assembled on the fe(3)o(4) nanoparticles (nps) were utilized as signal amplification sources. high-content hrp was adsorbed on the fe(3)o(4) nps via layer-by-layer (lbl) technique to prepare hrp-functionalized fe(3)o(4) nps. signal probe and diluting probe were then immobilized on the hrp-functionalized fe(3)o(4) nps through the bridge of au nps. thereafter, the resul ...201121376984
ph-tunable oxidase-like activity of cerium oxide nanoparticles achieving sensitive fluorigenic detection of cancer biomarkers at neutral ph.the reliable and sensitive detection of cancer-specific biomarkers is important for the diagnosis and treatment of cancer. hence, detection of these biomarkers has to be reliably and rapidly performed in diverse settings. a limitation of the conventional biomarker-screening method of enzyme-linked immunosorbent assay (elisa) is the employment of labile components, such as hydrogen peroxide and horseradish peroxidase. previously, we reported that nanoceria is able to oxidize various colorimertic ...201121370817
a highly efficient and versatile microchip capillary electrophoresis method for dna separation using gold nanoparticle as a tag.a highly efficient and versatile method for dna separation using au nanoparticles (au nps) as a tag based on microchip capillary electrophoresis (mce) was developed. the thiol-modified dna-binding au nps were utilized as a tag. target dna was sandwiched between au nps and probe dna labeled with horseradish peroxidase (hrp). in electrophoresis separation, the difference in electrophoretic mobility between free probe and probe-target complex was magnified by au nps, which enabled the resulting mix ...201121365742
enzymatic degradation of multiwalled carbon nanotubes.because of their unique properties, carbon nanotubes and, in particular, multiwalled carbon nanotubes (mwnts) have been used for the development of advanced composite and catalyst materials. despite their growing commercial applications and increased production, the potential environmental and toxicological impacts of mwnts are not fully understood; however, many reports suggest that they may be toxic. therefore, a need exists to develop protocols for effective and safe degradation of mwnts. in ...201121348486
the enzymatic oxidation of graphene oxide.two-dimensional graphitic carbon is a new material with many emerging applications, and studying its chemical properties is an important goal. here, we reported a new phenomenon--the enzymatic oxidation of a single layer of graphitic carbon by horseradish peroxidase (hrp). in the presence of low concentrations of hydrogen peroxide (∼40 μm), hrp catalyzed the oxidation of graphene oxide, which resulted in the formation of holes on its basal plane. during the same period of analysis, hrp failed to ...201121344859
fluorescence decrease of conjugated polymers by the catalytic activity of horseradish peroxidase and its application in phenolic compounds detection.we report the fluorescence decrease of the water-soluble π-π-conjugated polymer poly(2-methoxy-5-propyloxy sulfonate phenylene vinylene, mps-ppv) by the catalytic activity of horseradish peroxidase in the presence of h(2)o(2). mps-ppv acts as a donor substrate in the catalytic cycle of horseradish peroxidase where the electron-deficient enzymatic intermediates compounds i and ii can subtract electrons from the polymer leading to its fluorescence decrease. the addition of phenolic drug acetaminop ...201121341687
selective functionalisation of pdms-based photonic lab on a chip for biosensing.a comparative study of different approaches for the selective immobilisation of biomolecules on the surface of poly(dimethylsiloxane) (pdms) is reported. the motivation of this work is to set a robust and reliable protocol for the easy implementation of a biosensor device in a pdms-based photonic lab-on-a-chip (phloc). a hollow prism configuration, previously reported for the colorimetric detection of analytes was chosen for this study. here, the inner walls of the hollow prism were initially mo ...201121336349
small-scale, high-throughput method for plant n-glycan preparation for matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analysis.a simple, small-scale, and high-throughput method for preparation of plant n-glycans for matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (maldi-tof ms) is described. this method entailed the extraction of soluble proteins, pepsin digestion, release of n-glycans by glycopeptidase a, and a three-step chromatographic purification process using cation exchange, anion exchange, and graphitized carbon. homemade minicolumns using commercially available filter unit devices w ...201121320463
a simple assay for mammalian spermine oxidase: a polyamine catabolic enzyme implicated in drug response and disease.spermine oxidase (smo), the most recently characterized polyamine metabolic enzyme, catalyzes the direct back-conversion of spermine to spermidine in an fad-dependent reaction that also yields the byproducts hydrogen peroxide (h(2)o(2)) and 3-aminopropanal. these metabolites, particularly h(2)o(2), have been implicated in cytotoxic cellular responses to specific antitumor polyamine analogs, as well as in the inflammation-associated generation of dna damage. this chapter describes a rapid, sensit ...201121318873
immobilizing pt nanoparticles and chitosan hybrid film on polyaniline naofibers membrane for an amperometric hydrogen peroxide biosensor.a convenient and effective way for fabricating amperometric hydrogen peroxide (h2o2) biosensor was designed in this paper. first, the polyaniline (pani) nanofibers membrane with good conductance and high surface area was electropolymerized on a gold electrode surface. then, pt nanoparticle (ptnp) was electrochemically deposited on the pani nanofibers membrane. finally, the hybrid film of gold nanoparticle, chitosan, and horseradish peroxidase (hrp) was cast onto the modified electrode to form a ...201121318624
the use of hrp in decolorization of reactive dyes and toxicological evaluation of their products.this work studied the potential use of horseradish peroxidase (hrp) in the decolorization of the following textile dyes: drimarene blue x-3lr (dmblr), drimarene blue x-bln (dmbbln), drimarene rubinol x-3lr (dmr), and drimarene blue cl-r (rbbr). dyes were individually tested in the reaction media containing 120 mg·l(-1), considering the following parameters: temperature (20-45°c), h(2)o(2) concentration (0-4.44 mmol·l(-1)), and reaction time (5 minutes, 1 and 24 h). the following conditions: 35°c ...201121318147
degradation of pentachlorophenol by a novel peroxidase-catalyzed process in the presence of reduced nicotinamide adenine dinucleotide.a novel horseradish peroxidase (hrp)-catalyzed h₂o₂ process in the presence of reduced nicotinamide adenine dinucleotide (nadh) was applied to remove aqueous pentachlorophenol (pcp). parameters (ph, h₂o₂ concentration, hrp activity and nadh dosage) on pcp removal were investigated. it was found that initial 0.05mm pcp was removed by 98% in hrp-nadh-h₂o₂ system at ph 5.0 and 30°c for 1h. addition of o₂ in hrp-nadh-h₂o₂ system enhanced the removal rate of pcp due to promoting hydroxyl radicals (.o ...201121316072
influence of nanoreactor environment and substrate location on the activity of horseradish peroxidase in olive oil based water-in-oil microemulsions.oxidative enzymatic reactions using horseradish peroxidase (hrp) were carried out in water-in-oil (w/o) microemulsions composed of olive oil/lecithin/1-propanol/water, a model biomimetic system. the substrates used (gallic acid, octyl gallate and 2,2'-azino-bis[3-ethylbenzo-thiazoline-6-sulfonic acid] (abts)) have different hydrophobicities and possible locations in the microemulsion system. hrp reactivity with reference to substrate hydrophobicity and structural characteristics of the microemul ...201121314158
carcinoembryonic antigen admittance biosensor based on au and zno nanoparticles using fft admittance voltammetry.in this work, a highly sensitive carcinoembryonic antigen fast fourier transform admittance biosensor is introduced. the proposed biosensor is based on bilayer films of zno/au nanoparticles as an immobilization matrix. these layers are prepared by self-assembly and deposition method on a gold electrode surface, respectively. carcinoembryonic antibody (anti-cea) was immobilized on gold nanoparticles and positively charged horseradish peroxidase (hrp) was used to block sites against nonspecific bi ...201121309514
decolorization of naphthol blue black using the horseradish peroxidase.this study evaluates the potential of the enzyme horseradish peroxidase in the decolorization of one common industrial azo dye, naphthol blue black. studies are carried out to understand the process parameters such as ph, temperature and reaction time. the enzymatic decolorization of the dye was examined by uv-vis spectrophotometer and lc-ms measurements. temperature and ph conditions were optimized for obtaining high azo-dye decolorization. azo-dye removal at a ph range 4-6 was found to be the ...201120703828
oscillating chemiluminescence systems: state of the art.oscillating chemiluminescence (cl) was reported for the first time about 30 years ago. since then several systems based on addition of a chemiluminescent reagent to a known oscillator system or based on the light emitting features of one component of the oscillating system, have been described. this information, scattered in the scientific literature, is compiled in the present paper. several oscillating cl systems, including those based on belousov-zhabotinskii and orban oscillators, or horsera ...201120354969
determination of l-tyrosine based on luminescence quenching of mn-doped znse quantum dots in enzyme catalysis system.in this paper, we attempted to develop a novel application of mn-doped znse quantum dots (mn: znse d-dots) as probes to detect l-tyrosine (l-tyr). the bio-conjugates of horseradish peroxidase (hrp)-conjugated mn: znse d-dots were used in the enzyme catalyzed reaction of l-tyr with h(2)o(2.) compared with traditional cdte qds, mn: znse d-dots have better biocompatibility and less negative impact on enzyme catalyzed system. in hrp-conjugated mn: znse-l-tyr-h(2)o(2) system, electron transfer occurr ...201120614168
self-assembled, photoluminescent peptide hydrogel as a versatile platform for enzyme-based optical biosensors.a self-assembled peptide hydrogel consisting of fmoc-diphenylalanine has been employed as a biosensing platform through the encapsulation of enzyme bioreceptors (e.g., glucose oxidase or horseradish peroxidase) and fluorescent reporters (e.g., cdte and cdse quantum dots). enzymes and quantum dots (qds) were physically immobilized within the hydrogel matrix in situ in a single step by simply mixing aqueous solution containing qds and enzymes with monomeric peptide (fmoc-diphenylalanine) solution. ...201120171868
fabrication of a gel particle array in a microfluidic device for bioassays of protein and glucose in human urine samples.this paper describes a simple method for fabricating a series of poly(ethylene glycol) diacrylate (peg-da) hydrogel microstructures inside microfluidic channels as probe for proteins and glucose. in order to demonstrate the feasibility of this newly developed system, bovine serum albumin (bsa) was chosen as a model protein. peg microcolumns were used for the parallel detection of multiple components. using tetrabromophenol blue (tbpb) and the horseradish peroxidase/glucose oxidase reaction syste ...201122662039
fe₃o₄/au magnetic nanoparticle amplification strategies for ultrasensitive electrochemical immunoassay of alfa-fetoprotein.the purpose of this study was to devise a novel electrochemical immunosensor for ultrasensitive detection of alfa-fetoprotein based on fe(3)o(4)/au nanoparticles as a carrier using a multienzyme amplification strategy.201122228994
horseradish peroxidase: modulation of properties by chemical modification of protein and heme.horseradish peroxidase (hrp) is one of the most studied enzymes of the plant peroxidase superfamily. hrp is also widely used in different bioanalytical applications and diagnostic kits. the methods of genetic engineering and protein design are now widely used to study the catalytic mechanism and to improve properties of the enzyme. here we review the results of another approach to hrp modification-through the chemical modification of amino acids or prosthetic group of the enzyme. computer models ...201122339595
a multivariate approach to structural heterogeneity of retinal ganglion cells.knowing neuronal types is essential for understanding the structural and functional organization of the nervous system. it has long been recognized that neuronal types should be discovered and not defined. this can be done using cluster analysis (ca). despite there being many studies using ca to classify neurons, only a few of them meet its formal prerequisites. in the present study, we provide an example of using ca in combination with other multivariate techniques for examining neuronal divers ...201122192506
a sandwich electrochemical immunosensor using magnetic dna nanoprobes for carcinoembryonic antigen.a novel magnetic nanoparticle-based electrochemical immunoassay of carcinoembryonic antigen (cea) was designed as a model using cea antibody-functionalized magnetic beads [dna/fe(3)o(4)/zro(2); fe(3)o(4) (core)/zro(2) (shell) nano particles (zmps)] as immunosensing probes. to design the immunoassay, the cea antibody and o-phenylenediamine (opd) were initially immobilized on a chitosan/nano gold composite membrane on a glassy carbon electrode (gce/cs-nano au), which was used for cea recognition. ...201122174606
enzyme-polymers conjugated to quantum-dots for sensing applications.in the present research, the concept of developing a novel system based on polymer-enzyme macromolecules was tested by coupling carboxylic acid functionalized poly(vinyl alcohol) (pva-cooh) to glucose oxidase (gox) followed by the bioconjugation with cds quantum-dots (qd). the resulting organic-inorganic nanohybrids were characterized by uv-visible spectroscopy, infrared spectroscopy, photoluminescence spectroscopy (pl) and transmission electron microscopy (tem). the spectroscopy results have cl ...201122163736
simple chemiluminescence aptasensors based on resonance energy transfer.in the present work, two aptamer-based probes and related sensor systems were developed with chemiluminescence signaling. the detection was based on "turning-on" chemiluminescence with switching "off" of the resonance energy transfer after the aptamer's recognition of the target molecule. in this design, a dna/aptamer duplex linked a chemiluminescence group and a gold nanoparticle together. only low-intensity chemiluminescence was obtained due to the highly efficient resonance energy transfer. a ...201122156244
expression pattern of ck7 and ck20 in nasal polyps, at patients with chronic rhinosinusitis with nasal polyposis.we investigated the expression of cytokeratins 7 (ck7) and 20 (ck20) in nasal polyps on a group of 106 patients with chronic rhinosinusitis with nasal polyposis (45 women - 42% and 61 men - 58%) who benefited from surgical procedures. harvested biological material was analyzed in the pathology laboratory through two methods: histopathological and immunohistochemical analysis. classical histopathological method of processing the tissues initially fixed in 10% formalin was used. the tissues were t ...201122119824
green algae chlamydomonas reinhardtii possess endogenous sialylated n-glycans.green algae have a great potential as biofactories for the production of proteins. chlamydomonas reinhardtii, a representative of eukaryotic microalgae, has been extensively used as a model organism to study light-induced gene expression, chloroplast biogenesis, photosynthesis, light perception, cell-cell recognition, and cell cycle control. however, little is known about the glycosylation machinery and n-linked glycan structures of green algae. in this study, we performed mass spectrometry anal ...201123650571
immobilization of horseradish peroxidase onto a gold-nanoparticle-adsorbed poly(thionine) film for the construction of a hydrogen peroxide biosensor.an amperometric hydrogen peroxide (h2o2) biosensor was developed based on the immobilization of horseradish peroxidase (hrp) onto a gold-nanoparticle (gnp)-adsorbed conducting poly(thionine) (pth) film. the modification process was characterized by scanning electron microscope (sem), electrochemical impedance spectroscopy (eis) and cyclic voltammetry (cv). the effects of experimental parameters such as the concentration of the mediator (hydroquinone, hq), the ph of the solution, and the working ...201122121589
characterization of g-quadruplex/hemin peroxidase: substrate specificity and inactivation kinetics.recently, g-quadruplex/hemin (g4/hemin) complexes have been found to exhibit peroxidase activity, and this feature has been extensively exploited for colorimetric detection of various targets. to further understand and characterize this important dnazyme, its substrate specificity, inactivation mechanism, and kinetics have been examined by comparison with horseradish peroxidase (hrp). g4/hemin dnazyme exhibits broader substrate specificity and much higher inactivation rate than hrp because of th ...201122106035
fabrication of an electrochemical platform based on the self-assembly of graphene oxide-multiwall carbon nanotube nanocomposite and horseradish peroxidase: direct electrochemistry and electrocatalysis.a novel hybrid nanomaterial (go-mwnts) was explored based on the self-assembly of multiwall carbon nanotubes (mwnts) and graphene oxide (go). compared with pristine mwnts, such a nanocomposite could be well dispersed in aqueous solution and exhibit a negative charge. driven by the electrostatic interaction, positively charged horseradish peroxidase (hrp) could then be immobilized onto go-mwnts at the surface of a glassy carbon (gc) electrode to form a hrp/go-mwnt/gc electrode under mild conditio ...201122101607
preparation and characterization of bismuth oxide nanoparticles-multiwalled carbon nanotube composite for the development of horseradish peroxidase based h₂o₂ biosensor.in this work, preparation and characterization of a novel nanocomposite containing bismuth oxide (bi(2)o(3)) nanoparticles and multiwalled carbon nanotubes (mwcnts) was presented. powder x-ray diffraction (xrd) studies revealed that as-synthesized bi(2)o(3) nanoparticles are crystalline and belong to α-phase with monoclinic symmetry. field emission scanning electron microscopy (fesem) study results showed that the size of bi(2)o(3) nanoparticles is 50 nm. energy-dispersive x-ray (edx) spectra of ...201122099642
specifically and reversibly immobilizing proteins/enzymes to nitriolotriacetic-acid-modified mesoporous silicas through histidine tags for purification or catalysis.six nitriolotriacetic-acid-modified ordered mesoporous silicas (nta-ompss) with different pore sizes and surface features for specific and reversible protein immobilization were fabricated and characterized. specific immobilization of a genetically engineered undecaprenyl pyrophosphate synthase (upps) from cell lysate and a chemically modified his-tagged horseradish peroxidase (hrp) in these ni-nta-ompss through histidine coordination to the nickelated nta was demonstrated and confirmed by matri ...201122167883
detection of enzymatically generated hydrogen peroxide by metal-based fluorescent probe.we developed a metal-based fluorescent probe for h(2)o(2) called mbfh1, which has an iron complex as a reaction site for h(2)o(2) and a 3,7-dihydroxyphenoxazine derivative as the fluorescent reporter unit. the iron complex reacts quickly with h(2)o(2) to form oxidants, and then the oxidants convert the closely appended nonfluorescent 3,7-dihydroxyphenoxazine moiety to resorufin in an intramolecular fashion. the quick response to h(2)o(2) allows us to plot the enzymatic evolution of h(2)o(2). a c ...201122088146
a new fluorescent pet probe for hydrogen peroxide and its use in enzymatic assays for l-lactate and d-glucose.we present a new probe for the determination of hydrogen peroxide (hp). it is based on the yellow fluorophore 4-amino-1,8-napththalimide, coupled to p-anisidine (as a redox-active group) to form a probe that is based on photoinduced electron transfer (pet). the preparation of the probe (which we refer to as "hp green") was accomplished in four steps with good yield. its fluorescence is independent of ph in the physiological range and quenched by a pet process that occurs between the p-anisidine ...201122076816
a photoelectrochemical immunosensor for benzo[a]pyrene detection amplified by bifunctional gold nanoparticles.ultrasensitive photoelectrochemical immunoassay of polycyclic aromatic hydrocarbon (pah) is proposed using an antibody-modified nanostructured tio(2) electrode combined with bifunctional gold nanoparticles modified with the pah antigen and horseradish peroxidase (hrp). the hrp-catalyzed reaction prompts the electron transfer between the electrode and electrolyte causing an excellent photocatalytic performance.201122027936
antibody-based surfaces: rapid characterization using two complementary colorimetric assays.finding a general solution for optimizing the grafting of antibody on solid surfaces is difficult due to the variety of material, grafting principles and chemistries or surface formats available (beads, microplates, fibers, etc.). pre-screening methods able to assess grafting efficiency (ge) and specific activity (sa) are required. in this context, we present here two colorimetric assays that can be used on a wide variety of surface format, chemistry, etc. the first one, adeca (amino density est ...201122023873
a strategy for constructing sensitive and renewable molecularly imprinted electrochemical sensors for melamine detection.a novel strategy for preparing highly sensitive and easily renewable molecularly imprinted polymer (mip) sensors was proposed. using melamine (ma) as the template molecule, mip particles were synthesized and embedded in a solid paraffin carbon paste to prepare the mip sensor. ma was indirectly determined from the competition between the reactions of ma and horseradish peroxidase-labeled ma (ma-hrp) with the vacant cavities. the detection signals were amplified because of enzymatic reaction to th ...201122023859
a multi-amplification aptasensor for highly sensitive detection of thrombin based on high-quality hollow copt nanoparticles decorated graphene.in this work, we have successfully demonstrated a facile strategy to incorporate high-quality hollow copt bimetal alloy nanoparticles (hcopt) onto reduced graphene oxide sheet (hcopt-rgs). an advanced sandwich-type electrochemical aptasensor for thrombin was proposed by using the hcopt-rgs conjugates as secondary label. the formed conjugates provided large surface area for loading plentiful redox probe thionine (thi), horseradish peroxidase (hrp) and secondary aptamer (apt ii) with good stabilit ...201121944185
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