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bioactivity of horseradish peroxidase entrapped in silica nanospheres.interest in the fabrication of micro/nanoreactors for evaluation of the function of biomolecules in biological processes, enzymatic reaction kinetics occurring inside the nanospace is rapidly increasing. with a simple reverse-micelle microemulsion method, horseradish peroxidase (hrp), a model biomolecule, was herein skillfully confined in silica nanoshells (hrp@sio(2)) and its biocatalytical behaviors were investigated in detail. spectroscopic measurements showed that the entrapped hrp molecules ...201222410482
characterization of multifunctional nanosystems based on the avidin-nucleic acid interaction as signal enhancers in immuno-detection.the avidin-nucleic-acids-nano-assembly (ananas) is a kind of soft poly avidin nanoparticle originating from the high affinity interaction between avidin and the nucleic acids. in this work we investigated the possibility of transforming ananas cores into stoichiometrically controlled multifunctional nanoparticles through a "one-pot" procedure, and we measured in a quantitative way their ability to work as reagents for enhanced immunodiagnostic detection. initially, we measured the ananas loading ...201222414051
interenzyme substrate diffusion for an enzyme cascade organized on spatially addressable dna nanostructures.spatially addressable dna nanostructures facilitate the self-assembly of heterogeneous elements with precisely controlled patterns. here we organized discrete glucose oxidase (gox)/horseradish peroxidase (hrp) enzyme pairs on specific dna origami tiles with controlled interenzyme spacing and position. the distance between enzymes was systematically varied from 10 to 65 nm, and the corresponding activities were evaluated. the study revealed two different distance-dependent kinetic processes assoc ...201222414276
bioconjugated and cross-linked bionanostructures for bifunctional immunohistochemical labeling.the present study describes the development and use of a new bioconjugate combining targeted quantum dot labeling with an immunoperoxidase method and explores whether these bioconjugates could specifically and effectively label cu/zn superoxide dismutase (sod1). the new bioconjugate is designed for the examination of samples both under fluorescent and bright-field microscopy at the same time. for this purpose chlorobis(2-2'-bipyridyl) methacryloyl tyrosine-ruthenium(ii) and bis (2-2'-bipyridyl) ...201222414278
graphene-based chemiluminescence resonance energy transfer for homogeneous immunoassay.we report on chemiluminescence resonance energy transfer (cret) between graphene nanosheets and chemiluminescent donors. in contrast to fluorescence resonance energy transfer, cret occurs via nonradiative dipole-dipole transfer of energy from a chemiluminescent donor to a suitable acceptor molecule without an external excitation source. we designed a graphene-based cret platform for homogeneous immunoassay of c-reactive protein (crp), a key marker for human inflammation and cardiovascular diseas ...201222417160
double positivity to bee and wasp venom: improved diagnostic procedure by recombinant allergen-based ige testing and basophil activation test including data about cross-reactive carbohydrate determinants.specific ige (sige) antibodies to both bee and wasp venom can be due to a sensitivity to both insect venoms or due to cross-reactive carbohydrate determinants (ccds).201222421265
calcium carbonate-gold nanocluster hybrid spheres: synthesis and versatile application in immunoassays.fluorescent gold nanoclusters (auncs) were incorporated into porous calcium carbonate spheres through electrostatic interaction. the resulting caco(3)/auncs hybrid material exhibited interesting properties, such as porous structure, excellent biocompatibility, good water solubility, and degradability. these properties make the caco(3)/auncs hybrid material a promising template to assemble horseradish peroxidase/antibody conjugates (hrp-ab(2)). by using caco(3)/auncs/hrp-ab(2) bioconjugates as pr ...201222422592
dual photonic-electrochemical lab on a chip for online simultaneous absorbance and amperometric measurements.a dual lab on a chip (dloc) approach that enables simultaneous optical and electrochemical detection working in a continuous flow regime is presented. both detection modes are integrated for the first time into a single detection volume and operate simultaneously with no evidence of cross-talk. the electrochemical cell was characterized amperometrically by measuring the current in ferrocyanide solutions at +0.4 v vs gold pseudoreference electrode, at a flow rate of 200 μl min(-1). the experiment ...201222429156
reactive intermediates-induced potential responses of a polymeric membrane electrode for ultrasensitive potentiometric biosensing.reactive intermediates rather than stable reactants or products have been found to induce large potential responses on an appropriately formulated polymeric membrane electrode, which provides a novel methodology for ultrasensitive potentiometric biosensing based on the horseradish peroxidase-h(2)o(2) oxidation reaction.201222430082
γ-aminobutyric acid-, glycine-, and glutamate-immunopositive boutons on mesencephalic trigeminal neurons that innervate jaw-closing muscle spindles in the rat: ultrastructure and development.unlike other primary sensory neurons, the neurons in the mesencephalic trigeminal nucleus (vmes) receive most of their synaptic input onto their somata. detailed description of the synaptic boutons onto vmes neurons is crucial for understanding the synaptic input onto these neurons and their role in the motor control of masticatory muscles. for this, we investigated the distribution of γ-aminobutyric acid (gaba)-, glycine-, and glutamate-immunopositive (+) boutons on vmes neurons and their ultra ...201222430513
cross-linking of horseradish peroxidase adsorbed on polycationic films: utilization for direct dye degradation.horseradish peroxidase (hrp) was immobilized on the polyaniline (pani) grafted polyacrylonitrile (pan) films. the maximum hrp immobilization capacity of the pan-g-pani-3 film was 221 μg/cm(2). the hrp-immobilized pan-g-pani-3 film retained 79 % of the activity of the same quantity free enzyme. the hrp-immobilized pan-g-pani-3 film was operated for the decolorization of two different benzidine-based dyes in the presence of hydrogen peroxide. the maximum decolorization grade was obtained at ph 6.0 ...201222451080
functionalization of carbon buckypaper for the sensitive determination of hydrogen peroxide in human urine.here we report on a new approach for the electrochemical detection of hydrogen peroxide (h(2)o(2)) based on the co-immobilization of horseradish peroxidase and methylene blue on the functionalized carbon buckypaper supported by a titanium substrate. cyclic voltammetry was used to study and optimize the performance of the resulting electrochemical biosensor. the proposed biosensor exhibited high analytical performance towards the quantification of h(2)o(2) at the physiological ph 7.4. under optim ...201222459585
delivery of large molecules via poly(butyl cyanoacrylate) nanoparticles into the injured rat brain.poly(n-butyl-2-cyanoacrylate) (pbca) nanoparticles have been successfully applied to deliver small-molecule drugs to the central nervous system (cns). however, it is unclear whether pbca nanoparticles can be used as the delivery system for large molecules to potentially treat traumatic brain injury (tbi). in this study, we tested the capacity of pbca nanoparticles in passing through the blood-brain barrier (bbb) and transporting large molecules into normal and injured brains in the rat. we first ...201222460562
electrically contacted enzyme based on dual hairpin dna structure and its application for amplified detection of hg2+.in the present study, based on a dual hairpin dna structure, a novel system of electrically contacted enzyme and its signal amplification for ultrasensitive detection of hg(2+) was demonstrated. in the presence of hg(2+), with the interaction of thymine-hg(2+)-thymine (t-hg(2+)-t), dna sequence dully labeled with ferrocene (fc) at 5' end and horseradish peroxidase (hrp) at 3' end, hybridized to the capture probe and formed the dual hairpin structure on the electrode. fc unit acts as a relay that ...201222464917
dnazyme-based turn-on chemiluminescence assays in homogenous media.in this work, novel biosensing systems were developed for dnazyme-based assays in homogenous aqueous media. the two halves of a horseradish peroxidase mimicking dnazyme were assembled onto different gold nanoparticle surfaces through hybridization with corresponding linking dna sequences. in the analyses, the target molecules were recognized by the linking dna. this recognition broke the hybridization and released the dnazyme halves from the nanoparticle surface into the solution. together, both ...201222465444
suppressive effects of moringa oleifera lam pod against mouse colon carcinogenesis induced by azoxymethane and dextran sodium sulfate.moringa oleifera lam (horseradish tree; tender pod or fruits) is a major ingredient in thai cuisine and has some medicinal properties. previous studies have shown potentially antioxidant, antitumor promoter, anticlastogen and anticarcinogen activities both in vitro and in vivo. the present study was conducted to investigate chemopreventive effects on azoxymethane (aom)-initiated and dextran sodium sulfate (dss)-promoted colon carcinogenesis in mice. male icr mice were divided into 8 groups: grou ...201122471457
in vitro inhibitory activity of essential oil vapors against ascosphaera apis.this work evaluates the in vitro inhibitory activity of 70 essential oils (eos) in the vapor phase for the control of chalkbrood disease caused by ascosphaera apis maassen ex claussen (olive et spiltoir). two wild strains isolated from infected honey bee colonies together with one standard collection strain were tested by the microatmosphere method. from 70 eos, 39 exhibited an antifungal effect against a. apis standard and wild strains. the greatest antifungal action was observed for eo vapors ...201222474973
colorimetric detection of cholesterol with g-quadruplex-based dnazymes and abts2-.a novel colorimetric method for detection of cholesterol was developed with hemin-g-quadruplex dnazyme by transducing oxidation of cholesterol into the color change of 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (abts(2-)). oligonucleotide 5'-gtgggtagggcgggttgg-3' (oligo-1) formed g-quadruplex structure in the presence of k(+), it acted as a horseradish peroxidase (hrp) mimicking dnazyme when binding hemin and catalyzed the oxidation of colorless abts(2-) to green abts ...201222483213
detection of horseradish peroxidase-labeled reagents with diaminobenzidine/metal. 200622485708
detection of horseradish peroxidase-labeled reagents with chloronaphthol. 200622485709
detection of horseradish peroxidase-labeled reagents with aminoethylcarbazole. 200622485710
indirect detection using horseradish peroxidase-labeled reagents. 200622485844
antibody addition to drosophila specimens and detection using enzyme-linked reagents.introductionenzyme-linked reagents give excellent sensitivity and use a simple light microscope for detection. a range of enzymes is available, but for staining in situ, horseradish peroxidase will suit most needs. diaminobenzidine (dab) is one of the most sensitive substrates for horseradish peroxidase. it yields an intense brown product that is insoluble in both water and alcohol. it can be made more sensitive by adding metal salts such as cobalt or nickel to the substrate solution. the reacti ...200622485908
carbon nanospheres-promoted electrochemical immunoassay coupled with hollow platinum nanolabels for sensitivity enhancement.two nanostructures including carbon nanospheres-graphene hybrid nanosheets (cns-gns) and hollow platinum nanospheres (hptns) were first synthesized by using direct electrolytic reduction and wet chemistry methods, respectively. thereafter, a specific sandwich-type electrochemical immunoassay was designed for determination of carcinoembryonic antigen (cea) by using hptns-labeled horseradish peroxidase-anti-cea conjugates (hrp-anti-cea) as molecular tags and anti-cea-assembled cns-gps as sensing p ...201222487011
adipose tissue engineering using adipose-derived stem cells enclosed within an injectable carboxymethylcellulose-based hydrogel.in situ gelation of an aqueous solution of carboxymethylcellulose derivative bearing phenolic hydroxyl groups (cmc-ph) that contained suspended adipose-derived stem cells (ascs) was studied in vitro and in vivo for evaluating feasibility in adipose tissue-engineering strategies. the rat ascs that were enclosed in the cmc-ph gels through a horseradish peroxidase-catalysed reaction showed 92.8% viability, good proliferation and adipogenic differentiation in vitro. ten weeks after the subcutaneous ...201322489051
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
[influence of glucose concentration on the inhibition of streptococcus oligofermentans on streptococcus mutans].to investigate the inhibition of streptococcus oligofermentans (so) on streptococcus mutans (sm) and the producibility of hydrogen peroxide by so under the influence of glucose concentration environment.201222490221
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
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
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
magnetic beads-based enzymatic spectrofluorometric assay for rapid and sensitive detection of antibody against apxiva of actinobacillus pleuropneumoniae.in this paper, a simple, easily-operated and enzyme-amplified fluorescence immunoassay method using magnetic particles for the detection of antibody against actinobacillus pleuropneumoniae (app) has been presented. the a protein of app repeats-in-toxin iv (apxiva) with high specificity to the app species was immobilized onto the magnetic bead surfaces. horseradish peroxidase (hrp), which can catalyze the substrate 4-hydroxyphenylacetic acid (p-hpa), generating fluorescent bi-p, p'-hydroxyphenyla ...201222503209
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
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
[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
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
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
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
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
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
highly sensitive and selective colorimetric genotyping of single-nucleotide polymorphisms based on enzyme-amplified ligation on magnetic beads.herein we report a new strategy for highly sensitive and selective colorimatric assay for genotyping of single-nucleotide polymorphisms (snps). it is based on the use of a specific gap ligation reaction, horseradish peroxidase (hrp) for signal amplification, and magnetic beads for the easy separation of the ligated product. briefly, oligonucleotide capture probe functionalized magnetic beads are first hybridized to a target dna. biotinylated oligonucleotide detection probes are then allowed to h ...201622534103
fabrication of hydrogen peroxide biosensor based on ni doped sno2 nanoparticles.ni doped sno(2) nanoparticles (0-5 wt%) have been prepared by a simple microwave irradiation (2.45 ghz) method. powder x-ray diffraction (xrd) and transmission electron microscopy (tem) studies confirmed the formation of rutile structure with space group (p(42)/mnm) and nanocrystalline nature of the products with spherical morphology. direct electrochemistry of horseradish peroxidase (hrp)/nano-sno(2) composite has been studied. the immobilized enzyme retained its bioactivity, exhibited a surfac ...201622534105
modulation of tight junction proteins in the perineurium to facilitate peripheral opioid analgesia.peripheral application of opioids reduces inflammatory pain but is less effective in noninflamed tissue of rats and human patients. hypertonic solutions can facilitate the antinociceptive activity of hydrophilic opioids in noninflamed tissue in vivo. however, the underlying mechanisms are not well understood. we hypothesized that the enhanced efficacy of opioids may be because of opening of the perineurial barrier formed by tight junction-proteins like claudin-1.201222534246
disposable and integrated amperometric immunosensor for direct determination of sulfonamide antibiotics in milk.the preparation and performance of a disposable amperometric immunosensor, based on the use of a selective capture antibody and screen-printed carbon electrodes (spces), for the specific detection and quantification of sulfonamide residues in milk is reported. the antibody was covalently immobilized onto a 4-aminobenzoic acid (4-aba) film grafted on the disposable electrode, and a direct competitive immunoassay using a tracer with horseradish peroxidase (hrp) for the enzymatic labeling was perfo ...201622538058
microchip electrophoresis coupled with on-line magnetic separation and chemiluminescence detection for multiplexed immunoassay.a facile and universal strategy for multiplexed immunoassay is proposed. the strategy is based on microchip electrophoresis (mce) coupled with on-line magnetic separation and chemiluminescence (cl) detection. the system consisted of a microchip, an electromagnet, and a photomultiplier. the realization of multiplexed immunoassay protocol involves sampling magnetic nanoparticles (mnps) labeled antibodies, n-(4-aminobutyl)-n-ethyl-isoluminol (abei) labeled antigens and free antigens in the precolum ...201222539323
comparative study of surface plasmon resonance, electrochemical and electroassisted chemiluminescence methods based immunosensor for the determination of antibodies against human growth hormone.an indirect immunoassay format with human growth hormone (hgh) immobilized on the self-assembled monolayer (sam) modified surface plasmon resonance (spr) chip has been shown to detect specific anti-hgh antibodies using the combination of three different physical phenomena in the same channel of the spr analyzer. for the enhancement of analytical signal and sensitivity of the immunosensor horseradish peroxidase (hrp) labeled secondary antibodies, specifically interacting with the formed immune co ...201222541890
enhanced stability of horseradish peroxidase encapsulated in acetalated dextran microparticles stored outside cold chain conditions.micro- and nanoparticles have been shown to improve the efficacy of safer protein-based (subunit) vaccines. here, we evaluate a method of improving the vaccine stability outside cold chain conditions by encapsulation of a model enzyme, horseradish peroxidase (hrp), in an acid-sensitive, tunable biodegradable polymer, acetalated dextran (ac-dex). vaccines that are stable outside the cold chain would be desirable for use in developing nations. ac-dex particles encapsulating hrp were prepared using ...201222548844
understanding the formation of cus concave superstructures with peroxidase-like activity.copper sulfide (cus) concave polyhedral superstructures (cpss) have been successfully prepared in an ethanolic solution by a simple solvothermal reaction without the use of surfactants or templates. two typical well defined, high symmetry cus concave polyhedrons, forming a concave truncated cuboctahedron and icosahedron were prepared. the effect of the reaction time, temperature and different cu ion and sulfur sources on the formation of cus cpss were investigated and a possible formation mechan ...201222552534
quantum dot based rapid tests for zearalenone detection.three different kinds of immunosorbent assays with luminescence detection were developed for the determination of zearalenone (zen), a secondary toxic metabolite of fusarium fungi. cdse/zns core/shell quantum dots (qds) were used as a label in quantitative micro-well plate immunoassays (fluorescent-labeled immunosorbent assay, flisa) and in qualitative column test methods. as carriers for qd-based column tests, sepharose gel (for covalent binding of antibody) and polyethylene frits (for physical ...201222555674
poly(o-phenylenediamine)-carried nanogold particles as signal tags for sensitive electrochemical immunoassay of prolactin.a novel class of redox-active molecular tags, poly(o-phenylenediamine)-carried nanogold particles (gppds), was first synthesized and functionalized with horseradish peroxidase-anti-prolactin conjugates (hrp-anti-prl). thereafter, a specific sandwich-type electrochemical immunoassay was designed for determination of prolactin (prl) by using gppd-labeled hrp-anti-prl conjugates as molecular tags on anti-prl antibody-modified glassy carbon electrode. compared with pure gold nanoparticles and poly(o ...201222560276
the effect of chemical modification with pyromellitic anhydride on structure, function, and thermal stability of horseradish peroxidase.the stability of enzymes remains a critical issue in biotechnology. compared with the strategies for obtaining stable enzymes, chemical modification is a simple and effective technique. in the present study, chemical modification of horseradish peroxidase (hrp) was carried out with pyromellitic anhydride. hrp has achieved a prominent position in the pharmaceutical, chemical, and biotechnological industries. in this study, the effect of chemical modification on thermal stability, structure, and f ...201222562551
astrocytes acquire morphological and functional characteristics of ependymal cells following disruption of ependyma in hydrocephalus.hydrocephalic hyh mutant mice undergo a programmed loss of the neuroepithelium/ependyma followed by a reaction of periventricular astrocytes, which form a new cell layer covering the denuded ventricular surface. we present a comparative morphological and functional study of the newly formed layer of astrocytes and the multiciliated ependyma of hyh mice. transmission electron microscopy, immunocytochemistry for junction proteins (n-cadherin, connexin 43) and proteins involved in permeability (aqu ...201222576081
a novel double-coating carrier produced by solid-in-oil and solid-in-water nanodispersion technology for delivery of genes and proteins into cells.a novel intracellular delivery method both for genes and proteins is one of the most coveted systems in the drug delivery field. in the present study, we developed a double-coating carrier loaded with gene and protein produced by solid-in-oil and solid-in-water nanodispersion technology. the double-coating carriers did not require electrostatic interactions during the preparation so were able to encapsulate plasmid dna, ovalbumin (pi 4.5), horseradish peroxidase (pi 7.2), and cytochrome-c (pi 10 ...201222580226
development of an enzyme-linked immunoassay for the quantitation of influenza haemagglutinin: an alternative method to single radial immunodiffusion.the current method used to measure haemagglutinin (ha) content for influenza vaccine formulation, single radial immunodiffusion (srid), is lengthy and relies on the availability of matched standardised homologous reagents. the 2009 influenza pandemic highlighted the need to develop alternate assays that are able to rapidly quantitate ha antigen for vaccine formulation.201322583601
zymographic assay of oxidases using peroxidase or hemin entrapped in polyacrylamide gel.this chapter describes a zymographic assay of oxidases which is based on a coupled peroxidase or hemin reaction. the enzymatic activity of oxidases (i.e., diamine oxidase/dao, glucose oxidase, galactose oxidase) can be directly monitored on polyacrylamide gels containing horseradish peroxidase or hemin, in the presence of their specific substrates and ortho-phenylenediamine (opda), an oxidizable chromogen. in the presence of hydrogen peroxide, opda is oxidized to azo-aniline, which led to well-d ...201222585525
[enzymatic synthesis of electroconductive biocomposites based on dna and optically active polyaniline].electroconductive interpolymer polyaniline complexes are synthesized on the dna matrix, using the method of oxidative polymerization of aniline with two different biocatalyzers: horseradish root peroxidase and micropiroxidase-11 biomimetic. the spectral characteristics and morphology of the acquired biocomposites have been studied. the stereospecificity of the acquired samples of interpolymer complexes is shown, depending on the biocatalyzers used. the results acquired indicate the important rol ...201222586909
design and preparation of a nanoprobe for imaging inflammation sites.to image inflammation sites, we developed a novel nanoparticle, hydroxylamine-containing nanoparticle (hanp), which emits an intense electron spin resonance (esr)-signal triggered by enzymatic oxidation reaction and ph-sensitive self-disintegration. the nanoparticle was prepared from an amphiphilic block copolymer, poly(ethylene glycol)-b-poly[4-(2,2,6,6-tetramethylpiperidine-1-hydroxyl)aminomethylstyrene] (peg-b-pmnt-h), which spontaneously forms a core-shell type polymeric micelle (particle di ...201222589050
an integrated electrochemical device based on immunochromatographic test strip and enzyme labels for sensitive detection of disease-related biomarkers.a novel electrochemical biosensing device that integrates an immunochromatographic test strip and a screen-printed electrode (spe) connected to a portable electrochemical analyzer was presented for rapid, sensitive, and quantitative detection of disease-related biomarker in human blood samples. the principle of the sensor is based on sandwich immunoreactions between a biomarker and a pair of its antibodies on the test strip, followed by highly sensitive square-wave voltammetry (swv) detection. h ...201222608414
optimization of horseradish peroxidase-catalyzed enhanced chemiluminescence reaction by full factorial design.using a full factorial design the optimization of experimental conditions of enhanced chemiluminescence reaction (ecr) catalyzed by horseradish peroxidase (hrp-c) in the presence of 3-(10'-phenothiazinyl)propane-1-sulfonate (sptz) and 4-morpholinopyridine (morp) as enhancers was performed. the effect of concentrations of sptz, hydrogen peroxide, morp, luminol, and tris on a ratio of peroxidase-catalyzed cl to background was studied. the use of the full 2(5) factorial design instead of "one-varia ...201222608439
chromogen-based immunohistochemical method for elucidation of the coexpression of two antigens using antibodies from the same species.the authors established a chromogen-based, double immunolabeling method using antibodies from the same species without any unwanted cross-reactivity. in addition, time-consuming staining steps were shortened by using polymer-based secondary antibodies. taking advantage of the nature of the chromogen 3-amino-9-ethylcarbazole (aec), which is used as a horseradish peroxidase substrate for antibody detection, the aec-derived signals in the first color development were easily eliminated by alcohol tr ...201222610462
production of endothelial cell-enclosing alginate-based hydrogel fibers with a cell adhesive surface through simultaneous cross-linking by horseradish peroxidase-catalyzed reaction in a hydrodynamic spinning process.we developed an alginate-based hydrogel fiber enabling to enclose endothelial cells, degradable on-demand by alginate lyase, and having a cell adhesive surface. the hydrogel fiber was obtained by extruding an aqueous solution of 4% (w/v) alginate derivative possessing phenolic hydroxyl moieties (alg-ph) and horseradish peroxidase (hrp) into a flow of aqueous solution containing 0.3 mm h(2)o(2) and gelatin derivative possessing ph moieties (gelatin-ph). in the process, cross-linking of alg-ph res ...201222613056
rapidly curable chitosan-peg hydrogels as tissue adhesives for hemostasis and wound healing.chitosan-poly(ethylene glycol)-tyramine (cpt) hydrogels were rapidly formed in situ using horseradish peroxidase and hydrogen peroxide to explore their performance as efficient tissue adhesives. a poly(ethylene glycol) modified with tyramine was grafted onto a chitosan backbone to enhance the solubility of the chitosan and to crosslink into three-dimensional networks. the elastic modulus of the hydrogels could be controlled by changing the crosslinking conditions, and the mechanical strength inf ...201222617740
immobilized horseradish peroxidase on discs of polyvinyl alcohol-glutaraldehyde coated with polyaniline.discs of network polyvinyl alcohol-glutaraldehyde (pvag) were synthesized and coated with polyaniline (pani) using glutaraldehyde as a chemical arm (pvag-panig-hrp disc). the best conditions for the immobilization were established as about 1.0 mg ml(-1) of protein, for 60 min and ph 5.5. the soluble enzyme lost all of its activity after incubation at 70°c for 15 min, whereas the pvag-panig-hrp disc retained about half of the initial activity for pyrogallol. the same pvag-panig-hrp disc was used ...201222619582
quantification of peroxide ion passage in dentin, enamel, and cementum after internal bleaching with hydrogen peroxide.the aim of this study was to evaluate the amount of peroxide passage from the pulp chamber to the external enamel surface during the internal bleaching technique. fifty bovine teeth were sectioned transversally 5 mm below the cemento-enamel junction (cej), and the remaining part of the root was sealed with a 2-mm layer of glass ionomer cement. the external surface of the samples was coated with nail varnish, with the exception of standardized circular areas (6-mm diameter) located on the enamel, ...201522621165
antigen-capture enzyme-linked immunosorbent assays for detection of different h5 avian influenza a virus.avian influenza a virus (aiv) subtype h5 is divided into american and eurasian lineages, according to hemagglutinin gene sequences. although methods for detecting h5 aivs have been described, no h5 strain-specific detection method has been reported. the purpose of the present study was to develop an antigen-capture enzyme-linked immunosorbent assay (ace) to detect and differentiate between the american and the eurasian h5 aivs. monoclonal antibodies (mabs) against the ha fragment of a eurasian h ...201222621946
bi-enzyme synergetic catalysis to in situ generate coreactant of peroxydisulfate solution for ultrasensitive electrochemiluminescence immunoassay.a novel electrochemiluminescence (ecl) immunosensor for ultrasensitive detection of α-1-fetoprotein (afp) was designed based on the in situ bi-enzymatic reaction to generate coreactant of peroxydisulfate for signal amplification. in this work, aunps were electrodeposited on the glassy carbon electrode (gce) surface, which promoted the electron transfer. then, l-cysteine and another layer of aunps were, respectively assembled onto the modified electrode surface, which formed the multilayer films ...201222621981
multifunctional fe₃o₄ core/ni-al layered double hydroxides shell nanospheres as labels for ultrasensitive electrochemical immunoassay of subgroup j of avian leukosis virus.a novel electrochemical immunosensor for ultrasensitive detection of subgroup j of avian leukosis virus (alvs-j) was designed by using graphene sheets (gs)-layered double hydroxides (ldhs) composites modified electrode with multifunctional fe(3)o(4) core/ni-al ldhs shell (ldhs@fe(3)o(4)) nanospheres as labels. at first, the gs-ldhs were used for the immunosensor platform for improving the electronic transmission rate as well as increasing the surface area to capture a large amount of primary ant ...201522621982
[phenothiazines are slowly oxidizable substrates of horseradish peroxidase].reactions of peroxidase oxidation of triftazine and thioproperazine have been investigated in the presence of horseradish peroxidase using steady state kinetic methods. it has been shown that phenothiazines are slowly oxidizable substrates for horseradish peroxidase. k(cat) and k(m) values have been determined in the range of ph from 4.5 to 7.5. the study of co-oxidation of phenothiazines and o-dianisidine (odn) revealed that in the presence of aminazine and odn in the reaction medium both subst ...201422629605
opposing effects of diabetes and tetracycline on the degradation of collagen membranes in rats.increased collagenolytic activity, characteristic of uncontrolled diabetes, may compromise collagen membrane (cm) survival. tetracycline (tcn) possesses anticollagenolytic properties and delays cm degradation in healthy animals. this study evaluates the degradation of tcn--immersed and -non-immersed cms in rats with diabetes compared to those with normoglycemia.201322631880
a gene-protein assay for human epidermal growth factor receptor 2 (her2): brightfield tricolor visualization of her2 protein, the her2 gene, and chromosome 17 centromere (cen17) in formalin-fixed, paraffin-embedded breast cancer tissue sections.the eligibility of breast cancer patients for human epidermal growth factor receptor 2 (her2)-directed therapies is determined by the her2 gene amplification and/or her2 protein overexpression status of the breast tumor as determined by in situ hybridization (ish) or immunohistochemistry (ihc), respectively. our objective was to combine the us food and drug administration (fda)-approved her2 & chromosome 17 centromere (cen17) brightfield ish (bish) and her2 ihc assays into a single automated her ...201222647525
intact fibroblast growth factor 23 and fragments in plasma from gambian children.fibroblast growth factor 23 (fgf23) is grossly elevated in gambian children with rickets and, at a lower prevalence, in those without bone deformities. we used western blotting to mimic the detection capabilities of the c-terminal fgf23 enzyme-linked immunosorbent assay (elisa). only intact fgf23 hormone was present in gambian plasma samples from children with and without rickets.201322648001
oligonucleotide microarray for the identification of carbapenemase genes of molecular classes a, b, and d.this work is a report on the development of a method of hybridization analysis on dna microarrays for the simultaneous identification and typing of carbapenemase-encoding genes. these enzymes are produced by the microorganisms that are responsible for causing infectious diseases. the method involves several steps, including dna extraction from clinical samples and amplification of carbapenemase genes by multiplex pcr with simultaneous labelling by biotin. following that, hybridization of the lab ...201022649657
recombinant production of horseradish peroxidase conjugates with fab antibodies in pichia pastoris for analytical applications.recombinant immunoconjugates of marker enzymes with antigens or antibodies present considerably more advantages than those obtained by conventional methods of chemical synthesis; i.e. they are homogeneous, have a strictly determined stoichiometry, and retain the functional activity of both a marker protein and an antigen/antibody. based on the ppiczαb shuttle vector, we first managed to obtain a recombinant conjugate of key marker enzyme horseradish peroxidase (hrp) withfabfragments of antibodie ...201122649698
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
charge heterogeneity of monoclonal antibodies by multiplexed imaged capillary isoelectric focusing immunoassay with chemiluminescence detection.characterization of charge heterogeneity of recombinant monoclonal antibodies (mabs) requires high throughput analytical methods to support clone selection and formulation screens. we applied the nanopro technology to rapidly measure relative charge distribution of mabs in early stage process development. the nanopro is a multiplexed capillary-based isoelectric immunoassay with whole-column imaging detection. this assay offers specificity, speed and sensitivity advantages over conventional capil ...201222663182
enzyme activity assay for horseradish peroxidase encapsulated in peptide nanotubes.encapsulation of horseradish peroxidase (hrp) inside a peptide nanotube (pnt) was demonstrated and its activity was measured. enzyme assay verified that 0.16 μg of the enzymes were encapsulated in 1mg of pnts. the encapsulation was also verified with tem, uv-vis spectroscopy, and ftir. the activity of the encapsulated hrp was examined for thermal stability, long-term storage stability, and resistance to a denaturant. they showed good storage stability, retaining its activity up to 90%, while the ...201222664191
basic immunocytochemistry for light microscopy.immunocytochemistry, the identification of cell- or tissue-bound antigens in situ, by means of a specific antibody-antigen reaction, tagged microscopically by a visible label, has a remarkably wide range of applications. the basic techniques are straightforward and can be adapted to explore the localisation of virtually any molecule of interest to the researcher in samples of normal and/or malignant cells. heterogeneity can be mapped and loss or gain of immunoreactivity with tumour progression c ...201222674123
lectin histochemistry to detect altered glycosylation in cells and tissues.lectins are naturally occurring carbohydrate-binding molecules. a very wide range of purified lectins are commercially available which exhibit a diversity of carbohydrate-binding preferences. they can be used in the laboratory to detect carbohydrate structures on, or in, cells and tissues in much the same way that purified antibodies can be employed to detect cell- or tissue-bound antigens using immunocytochemistry. as lectins can distinguish subtle alterations in cellular glycosylation, they ar ...201222674124
immunoextraction of zinc proteins from human plasma using chicken yolk antibodies immobilized onto paramagnetic particles and their electrophoretic analysis.zinc(ii) as the only transition metal lacking redox activity is an essential part of approximately 10% proteins as a cofactor of these proteins. considering the fact that there are numerous zinc(ii) containing proteins, proteomics and metallomics studies aimed on them require accurate methods for preparation of real biological samples prior to their subsequent analysis using 2de and ms. for this purpose, we suggested a new method based on chicken anti-zinc antibodies and magnetizable particles. ...201222674189
carbon, hydrogen, and nitrogen isotope fractionation associated with oxidative transformation of substituted aromatic n-alkyl amines.we investigated the mechanisms and isotope effects associated with the n-dealkylation and n-atom oxidation of substituted n-methyl- and n,n-dimethylanilines to identify isotope fractionation trends for the assessment of oxidations of aromatic n-alkyl moieties by compound-specific isotope analysis (csia). in laboratory batch model systems, we determined the c, h, and n isotope enrichment factors for the oxidation by mno(2) and horseradish peroxidase (hrp), derived apparent (13)c-, (2)h-, and (15) ...201222681573
daf-fluorescence without no: elicitor treated tobacco cells produce fluorescing daf-derivatives not related to daf-2 triazol.diaminofluorescein-dyes (dafs) are widely used for visualizing no· production in biological systems. here it was examined whether daf-fluorescence could be evoked by other means than nitrosation. tobacco (nicotiana tabacum) suspension cells treated with the fungal elicitor cryptogein released compound(s) which gave a fluorescence increase in the cell-free filtrate after addition of daf-2 or daf-fm or dar-4m. daf-reactive compounds were relatively stable and identified as reaction products of h(2 ...201222683597
[development of a specific and sensitive enzyme-linked immunosorbent assay for vindesine].this paper reports a specific and sensitive enzyme-linked immunosorbent assay (elisa) for pharmacokinetic studies of vindesine (vds). anti-vds antibody was obtained by immunizing rabbits with vds conjugated with bovine serum albumin using n-[β-(4-diazophenyl) ethyl] maleimide as a heterobifunctional coupling agent. an enzyme marker was similarly prepared by coupling vds with horseradish peroxidase using n-(4-diazophenyl) maleimide. the detection limit of vds by elisa was approximately 24 pg/ml w ...201222687732
antioxidant activity of commonly consumed vegetables in yemen.of late, more attention has been paid to the role of natural antioxidants, especially phenolic compounds, which may act both by reducing the content of toxic compounds in foods and by supplying the human body with exogenous antioxidants. the total phenolic contents and the total antioxidant activities (% aa) of 17 commonly consumed vegetables in yemen were determined. total phenolics was measured colorimetrically using the folin-ciocalteu reagent with d-catechin as the standard. the antioxidant ...200222692476
a direct hippocampo-cerebellar projection in chicken.our previous studies suggested that a direct hippocampo-cerebellar projection might exist in the chicken. to confirm such a presumption of hippocampo-cerebellar interactions, horseradish peroxidase (hrp) was used as a retrograde tracer to be injected into the white matter of the folia vi-viii of the cerebellum in young and adult chickens. in another set of experiments, young chickens were subjected to electrolytic lesions of the hippocampal formation (hf), especially the ventromedial portion, an ...201222692931
a system to enrich for primitive streak-derivatives, definitive endoderm and mesoderm, from pluripotent cells in culture.two lineages of endoderm develop during mammalian embryogenesis, the primitive endoderm in the pre-implantation blastocyst and the definitive endoderm at gastrulation. this complexity of endoderm cell populations is mirrored during pluripotent cell differentiation in vitro and has hindered the identification and purification of the definitive endoderm for use as a substrate for further differentiation. the aggregation and differentiation of early primitive ectoderm-like (epl) cells, resulting in ...201222701686
dual amplification strategy of highly sensitive thrombin amperometric aptasensor based on chitosan-au nanocomposites.a highly sensitive and selective electrochemical aptasensor for thrombin was developed. by introducing chitosan-gold nanoparticles and horseradish peroxidase (cs-aunps-hrp) conjugates to the sensitive union, the thrombin detection signal was dual amplified. the capture probe was prepared by immobilizing an anti-thrombin aptamer on core-shell fe(3)o(4)-au magnetic nanoparticles (aumnps) and which was served as magnetic separation material as well. the detection probe was prepared from another ant ...201222701874
colorimetric detection of urine glucose based znfe2o4 magnetic nanoparticles.in this paper, we discovered that znfe(2)o(4) magnetic nanoparticles (mnps) possess intrinsic peroxidase-like activity. znfe(2)o(4) mnps exhibit several advantages such as high catalytic efficiency, good stability, monodispersion, and rapid separation over other peroxidase nanomimetics and horseradish peroxidase (hrp). znfe(2)o(4) mnps were used as a colorimetric biosensor for the detection of urine glucose. this method is simple, inexpensive, highly sensitive, and selective for glucose detectio ...201222702236
high expression of cd98 alters epithelial barrier functions to promote induction of airway allergy.epithelial barrier dysfunction is critical in the induction of allergy; the aetiology is to be further understood. a recent report indicates that cd98 plays a role in the intestinal epithelial barrier dysfunction.201222702504
boronic acid functionalized core-shell polymer nanoparticles prepared by distillation precipitation polymerization for glycopeptide enrichment.the boronic acid-functionalized core-shell polymer nanoparticles, poly(n,n-methylenebisacrylamide-co-methacrylic acid)@4-vinylphenylboronic acid (poly(mba-co-maa)@vpba), were successfully synthesized for enriching glycosylated peptides. such nanoparticles were composed of a hydrophilic polymer core prepared by distillation precipitation polymerization (dpp) and a boronic acid-functionalized shell designed for capturing glycopeptides. owing to the relatively large amount of residual vinyl groups ...201222707097
biological and enzymatic treatment of bisphenol a and other endocrine disrupting compounds: a review.bisphenol a is predominantly used as an intermediate in the production of polycarbonate plastics and epoxy resins. traces of bisphenol a released into the environment can reach into the wastewater and soil via application of sewage sludge from wastewater treatment systems that receive water containing bisphenol a, or from leachate from uncontrolled landfills. in this study we have made an effort to review the work on the presence of bisphenol a and other related endocrine disrupting compounds in ...201322712546
enzyme-linked small-molecule detection using split aptamer ligation.here we report an aptamer-based analogue of the widely used sandwich enzyme-linked immunosorbent assay (elisa). this assay utilizes the cocaine split aptamer, which is comprised of two dna strands that only assemble in the presence of the target small molecule. one split aptamer fragment is immobilized on a microplate, then a test sample is added containing the second split aptamer fragment. if cocaine is present in the test sample, it directs assembly of the split aptamer and promotes a chemica ...201222715870
a mechanistic study of the formation of hydroxyl radicals induced by horseradish peroxidase with nadh.during the oxidation of nadh by horseradish peroxidase (hrp-fe(3+)), superoxide (o(-)(2)) is produced, and hrp-fe(3+) is converted to compound iii. superoxide dismutase inhibited both the generation of o(-)(2) and the formation of compound iii. in contrast, catalase inhibited only the generation of o(-)(2). under anaerobic conditions, the formation of compound iii did not occur in the presence of nadh, thus indicating that compound iii is produced via formation of a ternary complex consisting of ...201222718789
screening of three commercial plant peroxidases for the removal of phenolic compounds in membrane bioreactors.a comparative study of three plant peroxidases, horseradish (hrp), soybean (sbp) and artichoke (akpc), was carried out to select the most appropriate one for 4-chlorophenol treatment in an ultrafiltration membrane reactor. soybean peroxidase showed the highest enzymatic activity, followed by hrp and akpc. the same tendency was observed in a discontinuous tank reactor, where sbp attained more than 90% of4-chlorophenol removal within the ph range tested. the optimum temperature was 30 degrees c, w ...201222720436
mgfe-layered double hydroxide modified electrodes for direct electron transfer of heme proteins.in this study, the fe-based layered double hydroxides (mg(3)fe ldh) were used to immobilize heme proteins including hemoglobin (hb), myoglobin (mb) and horseradish peroxidase (hrp) for fabrication of heme/mg(3)fe ldh film on glassy carbon electrode (mg(3)fe-heme/gce). the possible role of iron in framework of ldh to promote direct electron transfer (det) of heme proteins was investigated using an ldh containing non-iron as a reference. hb was selected as a model protein for studying the electroc ...201322721646
electrochemical immunoassay for cd10 antigen using scanning electrochemical microscopy.in the present study, a scanning electrochemical microscopic (secm) method for imaging of antigen/antibody binding was proposed using cd10 antigen as the model. on the basis of anti-cd10 modified electrode, an electrochemical immunosensor for sensitive detection of cd10 antigen at low potential was developed by a multiple signal amplification strategy. gold nanoparticles (aunps) served as carriers to load more secondary antibodies (ab(2)) and horseradish peroxidase (hrp). the tip ultramicroelect ...201222727518
sensitive csf elisas for the detection of mbl, masp-2 and functional mbl/masp-2.mannose binding lectin (mbl) mediated complement pathway is an important constituent of innate immune response in several infections including neuroinflammatory and neurodegenerative diseases. although there are enzyme-linked immunosorbent assays (elisas) for estimating mbl, mbl-associated serine protease-2 (masp-2) and functional mbl-masp-2 (fmbl) proteins for the plasma, serum and cell supernatants there are no established methods for their estimation in the cerebrospinal fluid (csf). we devel ...201222728252
heterologous enzyme linked immunosorbent assay for measurement of testosterone in serum.in steroid enzyme immunoassay (eia), homologous and heterologous combinations of enzyme conjugate with immunogen influences labeled steroid recognition by antibodies that affect sensitivity of the assay. to develop testosterone enzyme linked immunosorbent assay (elisa), antibodies were generated against testosterone-3-carboxymethyloxime-bovine serum albumin (t-3-cmo-bsa), testosterone-11-hemisuccinate-bovine serum albumin (t-11-hs-bsa), testosterone-17-hemisuccinate-bovine serum albumin (t-17-hs ...201222738649
a fluorescently labeled dendronized polymer-enzyme conjugate carrying multiple copies of two different types of active enzymes.a hybrid structure of a synthetic dendronized polymer, two different types of enzymes (superoxide dismutase and horseradish peroxidase), and a fluorescent dye (fluorescein) was synthesized. thereby, a single polymer chain carried multiple copies of the two enzymes and the fluorescein. the entire attachment chemistry is based on uv/vis-quantifiable bis-aryl hydrazone bond formation that allows direct quantification of bound molecules: 60 superoxide dismutase, 120 horseradish peroxidase, and 20 fl ...201222741539
a feasible enzyme-linked immunosorbent assay system using monoclonal and polyclonal antibodies against glucosyltransferase-b from streptococcus mutans.streptococcus mutans has been considered the principal etiological agent of dental caries in humans. s. mutans can secrete three kinds of glucosyltransferases (gtfs). one of these, gtf-b, which synthesizes water-insoluble glucans from sucrose, has been considered to be one of the most important factors of cariogenic dental plaque formation. therefore, determination of whether gtf-b is present in plaque and saliva samples may contribute to the evaluation of individual virulence potential (caries ...201222741581
gold nanoparticle-enzyme conjugates based fret for highly sensitive determination of hydrogen peroxide, glucose and uric acid using tyramide reaction.in this paper, we report a new strategy for highly sensitive determination of hydrogen peroxide, glucose and uric acid based on fluorescence resonance energy transfer (fret) using gold nanoparticles (aunps) as energy acceptors. the principle is based on highly sensitive reaction of tetramethyl rhodamine (tmr) labeled tyramide and hydrogen peroxide catalysed by horseradish peroxidase (hrp), and the fluorescence spectrum of tmr (ex(max) 575 nm) partially overlaps with the visible absorption bands ...201222745932
improvement in determination of isothiocyanates using high-temperature reversed-phase hplc.the largely adopted reversed-phase hplc analysis of the molecular species of isothiocyanates (itcs) was performed and showed losses during the chromatographic run with eight itcs. these losses, which obviously impact the accuracy of quantitative determinations, were due to precipitation in the chromatographic system. at 22°c, they ranged from 5.4% for sulforaphane (sfn) to 11.0% for benzyl-itc when itcs were injected at 80 μg ml(-1) , but they were up to three times higher at 1 mg ml(-1) reachin ...201222752995
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