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Abstract
Effective immobilization of antibodies on a sensing platform and sensitivity enhancement are crucial in designing surface plasmon resonance (SPR) immunosensors. Colloidal gold nanoparticles (AuNPs) were directly assembled onto a surface of SPR Au chip via 2-aminoethanethiol for the enhancement of sensitivity as a label-free detection system. SEM image showed most AuNPs were uniformly distributed over the surface. A novel fusion protein was constructed by genetically fusing gold binding polypeptides (GBP) to protein A (ProA) as a crosslinker for effective immobilization of ...
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Biosensors & bioelectronics, Vol. 19, No. 3. (30 November 2003), pp. 185-192
Abstract
The self-assembled layer of modified protein A was fabricated. In order to modify protein A, the surface group of protein A was substituted with thiol (-SH) functionality by using N-succinimidyl-3-(2-pyridyldithio)propionate (SPDP) and dithiothreitol (DTT). The formation of a self-assembled protein A layer on a Au substrate and its increased binding capacity to antibody were confirmed by surface plasmon resonance (SPR) spectroscopy. The surface structure of ...
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Abstract
Coupling of ferrocene moieties to avidin via a flexible spacer mol. yields a conjugate which combines the unique biotin-binding properties of avidin with the reversible redox characteristics of ferrocenes. Synthesis of the conjugate has been optimized and the conjugates were characterized bio- and electrochem. Covalent immobilization of the conjugate on gold electrodes in a dense monolayer results in electrodes with a high binding capacity for biotinylated mols. as well as good electron transfer properties. The application potential of ...
Note (first note only)
CAPLUS AN 2000:853714(Journal)
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Abstract
The authors report here an enzyme-amplified, sandwich-type immunosensor for detecting the biospecific interaction between an antibody and antigen using redox mediation. The authors employed biotin/anti-biotin IgG as a model immunosensing pair. Partially ferrocenyl-tethered dendrimer (Fc-D), whose ferrocene moiety acts as a redox mediator, was immobilized to the electrode surface by covalent binding between the dendrimer amines and the carboxylic acids of a self-assembled monolayer. The unreacted amines of the immobilized Fc-D were modified with biotin groups to allow ...
Note (first note only)
CAPLUS AN 2006:169426(Journal)
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Abstract
In this paper, a highly sensitive, reagentless, electrochem. strategy is reported for the detection of a cancer biomarker - Vascular Endothelial Growth Factor (VEGF). Disk-shaped carbon fiber microelectrodes were used as the immunosensor platform. Ferrocene monocarboxylic acid-labeled anti-VEGF was covalently immobilized on the microelectrode surface using a Jeffamine cross-linker. The formation of immunocomplexes led to a decrease in the electrochem. signal of ferrocene monocarboxylic acid owing to increased spatial blocking of the microelectrode surface. These signal changes ...
Note (first note only)
CAPLUS AN 2009:872184(Journal)
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Abstract
A novel amperometric immunosensor for determination of human serum chorionic gonadotrophin (HCG) was constructed by immobilization of HCG with titania sol–gel on a glassy carbon electrode and the direct electrochemistry of horseradish peroxidase (HRP) labeled to HCG antibody (HRP- anti -HCG). The morphologies of the HCG membrane were characterized to be chemically clean, porous and homogeneous. HRP- anti -HCG was functionally conjugated with the immobilized HCG after incubation in phosphate buffer (PBS) containing HRP- anti -HCG. A direct electron transfer of ...
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posted to antibody immunosensor protein_a
by mdelvalle
on 2009-11-09 19:50:49
Abstract
A novel rigid and renewable transducing material for electrochemical immunosensing, based on Protein A bulk-modified graphite-epoxy biocomposite (ProtA-GEB) is reported. Protein A is able to bind to the Fc region of antibodies and provide an affinity matrix for antibody immobilisation onto the transducer. The rigid conducting biocomposite acts not only as a transducer, but also as a reservoir for protein A. After use, the electrode surface can be renewed by a simple polishing procedure, highlighting a clear advantage of this new ...
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Abstract
Staphylococcal enterotoxins (SEs) are major cause of foodborne diseases, so sensitive detection (< 1 ng/ml) methods are needed for SE detection in food. The surface area, geometric and physical properties of gold nanoparticles make them well-suited for enhancing interactions with biological molecules in assays. To take advantage of the properties of gold nanoparticles for immunodetection, we have developed a gold nanoparticle-based enhanced chemiluminescence (ECL) immunosensor for detection of Staphylococcal Enterotoxin B (SEB) in food. Anti-SEB primary antibodies were immobilized onto a gold nanoparticle ...
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Abstract
Abstract A competitive immunosensor using a monoclonal antibody has been developed for the enumeration of Nitrobacter in activated sludge and other environmental samples. Its cross-reactivity was tested against a number of bacterial strains and isolates. All strains of the nitrite-oxidising genera Nitrobacter and Nitrococcus reacted strongly with the monoclonal antibody. The nitrite-oxidising Nitrospira moscoviensis, as well as the ammonia oxidising bacteria and the heterotrophic bacteria tested, did not show any affinity towards the antibody in the immunosensor. The numbers of Nitrobacter ...
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Abstract
A new amperometric enzyme-linked immunoassay for specific enumeration of Nitrobacter has been developed. This assay uses an electrode made of glassy carbon, on which the immunological reaction is carried out. The method is based on a competitive immunoassay principle, utilising monoclonal primary antibody and alkaline-phosphatase-labelled secondary antibody. The enzyme substrate 5-bromo-4-chloro-3-indolyl phosphate generates an electroactive product which is amperometrically detected. The effects of different parameters on the performance of the sensor have been studied. Quantitative detection of Nitrobacter using the immunosensor ...
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Abstract
In contrast to optical immunosensors, the electrochemical detection of an immunanalytical reaction does require a labeling, but allows an easier discrimination of specific and non-specific binding. We present a concept and first results for a multivalent amperometric immunosensor system which is based on silicon technology. The capture molecule streptavidin, covalently immobilized on silica, allows the immobilization of biotinylated antigens at a defined density. A nanostructured gold electrode serving as a stable network of nanowires is expected to be beneficial for the ...
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Abstract
A new chip-based electrochemical immunoassay protocol, based on the use of a ferrocene redox label, is described. Two reaction formats, based on direct (noncompetitive) and competitive modes of operation, were employed for illustrating the use of redox tracers in chip-based electrochemical immunoassays. The direct assay consisted of mixing the ferrocene-tagged antibody and the antigen analyte, a rapid electrophoretic separation of labeled free antibody and the labeled antigen/antibody complex, and a downstream anodic detection of the ferrocene tracer at gold-plated carbon screen-printed ...
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Abstract
An amperometric immunosensor based on a rigid immunocomposite was built to measure human chorionic gonadotropin [beta]-subunit ([beta]-HCG). The immunocomposite is formed by a conducting graphite-methacrylate matrix containing the anti-[beta]-HCG antibody. The main advantage of this kind of immunosensors is their easy regeneration which can be achieved by a simple polishing of their surface. [beta]-HCG is determined with a sandwich assay using anti-[beta]-HCG conjugate labelled with horseradish peroxidase (HRP). The extent of the immunological interaction is quantified by the activity of the ...
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Abstract
The repeated use of immunochemically modified solid phases in electrochemical immunosensor analysis is the driving interest of this work. Two new strategies have been developed. One of these strategies is aimed at the development of a manual methodology. It comprises the construction of amperometric immunosensors based on rigid biocomposites. These biocomposites are formed by a conducting polymer composite matrix that acts as a reservoir of an immobilized immunologic material. The surface of the biocomposite can be renewed by a simple polishing ...
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Clin Biochem, Vol. 32, No. 3. (April 1999), pp. 229-231
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Acta Anaesthesiol Scand Suppl, Vol. 111 (1997), pp. 289-292
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Biosens Bioelectron, Vol. 18, No. 11. (1 October 2003), pp. 1321-1327
Abstract
A concept based on the Peroxidase-chip (P-chip), antibody co-immobilization, competitive and enzyme-channeling principle was exploited to develop an integrated flow-through amperometric biosensor for detection of environmental pollutants such as s-triazine herbicides. In this concept, recombinant peroxidase is immobilized on the gold electrode (P-chip) in such a way that direct electron transfer is achieved. The recognition and quantitation the target analyte is realized through the competition between the simazine-glucose oxidase (GOD) conjugate and free simazine for the binding sites of the monoclonal ...
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Abstract
A concept based on the Peroxidase-chip (P-chip), antibody co-immobilization, competitive and enzyme-channeling principle was exploited to develop an integrated flow-through amperometric biosensor for detection of environmental pollutants such as s-triazine herbicides. In this concept, recombinant peroxidase is immobilized on the gold electrode (P-chip) in such a way that direct electron transfer is achieved. The recognition and quantitation the target analyte is realized through the competition between the simazine-glucose oxidase (GOD) conjugate and free simazine for the binding sites of the monoclonal ...
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Abstract
Immunoanalytical techniques have found widespread use due to the characteristics of specificity and wide applicability for many analytes, from large polymer antigens, to simple haptens, and even single atoms. Electrochemical sensors offer benefits of technical simplicity, speed and convenience via direct transduction to electronic equipment. Together, these two systems offer the possibility of a convenient, ubiquitous assay technique with high selectivity. However, they are still not widely used, mainly due to the complexity of the associated immunoassay methodologies. A separation-free immunoanalytical ...
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Abstract
In this work, a disposable electrochemical immunosensor, based on a competitive assay scheme, was applied to detect polychlorinated biphenyls (PCBs) in food. For this purpose, antibodies against PCBs were directly immobilized onto the carbon surface of a disposable screen-printed electrode. A competition between the PCBs present in the sample and a fixed concentration of an enzyme-labeled PCB was realized and evaluated by electrochemical detection. Alkaline phosphatase was used as the enzyme label, coupled with differential pulse voltammetry (DPV) as the electrochemical ...
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Abstract
Novel polishable immunosensors based on rigid biocomposite materials have been constructed. These biocomposites contain graphite powder, rabbit IgG, and methacrylate or epoxy resins. This material acts as a reservoir for the biological molecules and as a transducer at the same time. In order to study the potential analytical properties of this new type of material, a competitive binding assay was developed to determine the RIgG present in a sample with the aid of goat anti-rabbit IgG labeled with alkaline phosphatase. Using ...
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posted to amperometry e-c-i-a immunosensor
by biblio24
on 2008-12-01 15:44:18
Abstract
An amperometric, enzyme-channeling immunosensor was used to study the qualitative and quantitative aspects of molecular biorecognition in real time. The immunosensor consisted of a polyethylenimine-modified carbon electrode on which glucose oxidase was coimmobilized with a specific antibody or with calmodulin. The immunological reactions were monitored electrochemically in situ, and the binding curves were directly visualized on a computer screen. This approach was applied for estimating the kinetic constants of the reaction between IgG and its specific anti-IgG antibodies, as well as ...
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Abstract
An immunosensor for the detection of Vibrio cholerae O1 was developed on the basis of surface plasmon resonance (SPR). A protein G layer was fabricated by means of the chemical coupling between the free amine (-NH2) groups of protein G and the activated carboxyl groups present on a self-assembled monolayer (SAM) consisting of a mixture of 11-mercaptoundecanoic acid (MUA) and hexanethiol (molar ratio of 1:2). A monoclonal antibody, which was confirmed to be specific to V. cholera O1 by the Western ...
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Abstract
An immunosensor for the detection of Vibrio cholerae O1 was developed on the basis of surface plasmon resonance (SPR). A protein G layer was fabricated by means of the chemical coupling between the free amine (-NH2) groups of protein G and the activated carboxyl groups present on a self-assembled monolayer (SAM) consisting of a mixture of 11-mercaptoundecanoic acid (MUA) and hexanethiol (molar ratio of 1:2). A monoclonal antibody, which was confirmed to be specific to V. cholera O1 by the Western ...
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Abstract
4-Aminophenyl phosphate (4-APP) and 1-naphthyl phosphate (1-NP) were compared as enzyme substrates for an amperometric milk progesterone biosensor utilising progesterone-conjugated alkaline phosphatase in a competitive immunoassay format. Cyclic voltammetry of the corresponding hydrolysis products, 4-aminophenol and 1-naphthol, at the surface of screen-printed carbon base transducers, uncoated or coated with anti-progesterone monoclonal antibody (mAb) showed well-defined anodic responses for both species, with the more sensitive being 4-aminophenol. Scan rate studies produced evidence that surface mAb could impede the diffusion of 4-aminophenol, but ...
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Abstract
This paper presents a new disposable amperometric, enzyme-channeling immunosensor for a quantitative, rapid, separation-free enzyme immunoassay (EIA) that can be used in clinical diagnostics, as well as in biomedical, biochemical, and environmental research. The sensor consists of a disposable, polymer-modified, carbon electrode on which enzyme 1 is coimmobilized with a specific antibody that binds the corresponding antigen in a test solution. The solution also contains a conjugate of enzyme 2. An immunological reaction brings the two enzymes into close proximity at ...
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Abstract
The microfabrication of electrochemical immunosensors for the simultaneous detection of two protein analytes is described. The sensors consisted of two iridium oxide electrodes (1-mm diameter) patterned on a glass substrate. Capture antibodies were immobilized on the porous iridium oxide electrodes by covalent attachment using (3-aminopropyl)triethoxysilane and glutaraldehyde. The spatial separation of the electrodes (2.5 mm) enabled simultaneous electrochemical immunoassays to be conducted without cross-talk between the electrodes. Proteins were measured using electrochemical ELISA, and detection was achieved by electrochemically oxidizing alkaline ...
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Anal. Chem. In Analytical Chemistry, Vol. 78, No. 8. (17 March 2006), pp. 2507-2513, doi:10.1021/ac0518452
Abstract
A novel amperometric biosensor for performing simultaneous electrochemical multianalyte immunoassays is described. The sensor consisted of eight iridium oxide sensing electrodes (0.78 mm2 each), an iridium counter electrode, and a Ag/AgCl reference electrode patterned on a glass substrate. Four different capture antibodies were immobilized on the sensing electrodes via adsorption. Quantification of proteins was achieved using an ELISA in which the electrochemical oxidation of enzyme-generated hydroquinone was measured. The spatial separation of the electrodes enabled simultaneous electrochemical immunoassays for multiple proteins ...
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Abstract
An electrochemical immunosensor for performing multianalyte measurements of tumor markers is described. The sensor consisted of an array of immunosensing electrodes fabricated on a glass substrate. Each electrode contained a different immobilized antigen and was capable of measuring a specific tumor marker using electrochemical enzyme-based competitive immunoassay. Using this arrangement, multiple analytes could be measured simultaneously by performing the technical operations for a single assay. The biosensor was used to measure the concentrations of seven important tumor markers: AFP, ferritin, CEA, ...
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Abstract
Abstract A micro-analytical system for rapid and quantitative analysis by inhibition immunoassay is presented and applied to the detection of folic acid. Eight polymer microchannels of 65-nL volume each and containing microelectrodes are embedded in a cartridge so that they can be operated simultaneously. All fluidic steps as well as the amperometric detection in the channels are operated by an instrument and software developed in-house. The fluidic steps of the immunoassay occur through hydrodynamic loading of the different solutions through the channels. ...
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Abstract
To realize highly sensitive electrochemical immunoassays, a micro-fabricated three-dimensional (3D) electrode was fabricated and applied to enzyme immuno assay based on production of a redox species. The dimensions of the electrodes are 10 microm in width and 30 microm in height, with 20 microm spacing in between, and the 30 pairs of anode and cathode electrodes made up a single sensor. This structure lead to enhancement of the electrochemical reaction, nearly 100% of trap ratio of redox species. It can be ...
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posted to amperometry immunosensor
by biblio24
on 2007-06-18 11:11:25
Abstract
A novel immunosensor for rapid separation-free determination of carcinoembryonic antigen (CEA) in human serum is proposed. The immunosensor is prepared by co-immobilizing thionine and horseradish peroxidase (HRP)-labeled CEA antibody on a glassy carbon electrode (GCE) through covalently binding them to GCE with a glutaraldehyde (GA) linkage. The electrochemical behavior of the immobilized thionine displays a surface-controlled electrode process with an average electron transfer rate constant of 4.74+/-2.99 s-1. It can be used as an electron transfer mediator for enzymatic activity detection ...
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Abstract
This paper discusses basic electrochemical immunoassay technology. Factors limiting the practical application of antibodies to analytical problems are also presented. It addresses the potential use of immunoassay methods based on electrochemical detection for the analysis of environmental samples. It provides examples for the detection and quantitation of environmental samples using conducting electroactive polymers (CEPs). CEP-based immunosensing systems are compared with conventional environmental immunoassay procedures. The advantages of using these types of sensors for rapid, sensitive, and cost-effective analysis of pesticides and ...
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Abstract
We report a novel method of electrochemical signaling from antigen-antibody interactions at immunoelectrodes with bioelectrocatalyzed enzymatic signal amplification. For the immunosensing surface construction, a poly(amidoamine) G4-dendrimer was employed not only as a building block for the electrode surface modification but also as a matrix for ligand functionalization. As a model biorecognition reaction, the dinitrophenyl (DNP) antigen-functionalized electrode was fabricated and an anti-DNP antibody was used. Glucose oxidase (GOX) was chosen to amplify electrochemical signal by enzymatic catalysis. The signal amplification strategy ...
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Journal of Electroanalytical Chemistry, Vol. 596, No. 2. (1 November 2006), pp. 109-116
Abstract
The aim of our study was to prospectively evaluate the potential diagnostic value and clinical applicability of label-free electrochemical detection of human telomerase reverse transcriptase (hTERT). The expression of human telomerase reverse transcriptase (hTERT) was analyzed by adsorptive transfer differential pulse stripping voltammetry (DPSV) from the cell lysates prepared from the urine samples of consenting adults. The principle of the electrochemical determination relies on the intrinsic electro-activity of the proteins. Tyrosine (Tyr), Tryptophan (Trp) and Cysteine (Cys) residues in proteins are ...
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Enzyme and Microbial Technology, Vol. 39, No. 5. (4 September 2006), pp. 1122-1127
Abstract
This paper reports a rapid microchip-based electrochemical enzyme immunoassay with surface-functionalized poly(dimethylsiloxane) (PDMS) channel. The microchip fabricated on a glass substrate by photolithography consists of a three-electrode system for electrochemical detection and is assembled with the antibody-immobilized PDMS channel by plasma treatment. For effective immobilization of target antibodies, the internal surface of the PDMS channel is chemically modified into the silane monolayer containing poly(ethyleneglycol) (PEG) groups, which minimize non-specific binding. Due to low height (50 [mu]m) of the channel dimensions, the ...
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Sensors and Actuators B: Chemical In Special Issue - In honour of Professor Karl Cammann, Vol. 113, No. 2. (27 February 2006), pp. 692-699
Abstract
An amperometric immunosensor for rapid determination of 17-[beta] estradiol (17-[beta]-E2) was developed. The immunosensor was based on disposable screen-printed carbon electrodes. Both monoclonal and polyclonal antibodies were assessed and the use of monoclonal antibodies resulted in a more sensitive assay. Detection was facilitated by labelling the antibody with alkaline phosphatase and amperometric measurements were performed at +300 mV versus Ag/AgCl using p-aminophenyl phosphate (p-APP) as substrate. The sensor could detect 17-[beta]-estradiol in an environmentally relevant range with a detection limit of ...
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Abstract
An amperometric immunosensor for the specific and simple detection of 3,4-methylenedioxyamphetamine (MDA) and its analogues, 3,4-methylenedioxymethamphetamine (MDMA) and 3,4-methylenedioxyethylamphetamine (MDEA) in saliva and urine was developed. A direct competitive assay in which free analyte and horseradish peroxidase labelled species were simultaneously added to an immobilised polyclonal antibody was employed. Both MDA and MDMA could be labelled with the enzyme and the use of an MDMA-HRP tracer greatly enhanced the sensitivity of the assay. Amperometric detection was performed at +100 mV versus ...
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Biosensors and Bioelectronics, Vol. 21, No. 2. (15 August 2005), pp. 330-336
Abstract
A novel amperometric immunosensor for determination of human serum chorionic gonadotrophin (HCG) was constructed by immobilization of HCG with titania sol-gel on a glassy carbon electrode and the direct electrochemistry of horseradish peroxidase (HRP) labeled to HCG antibody (HRP-anti-HCG). The morphologies of the HCG membrane were characterized to be chemically clean, porous and homogeneous. HRP-anti-HCG was functionally conjugated with the immobilized HCG after incubation in phosphate buffer (PBS) containing HRP-anti-HCG. A direct electron transfer of HRP with a rate constant of ...
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Clin Chem, Vol. 41, No. 9. (September 1995), pp. 1378-1384
Abstract
A novel nonseparation electrochemical enzyme immunoassay (NEEIA) for detecting marker proteins in undiluted blood is described. The approach is based on preferential electrochemical measurement of surface-bound enzyme-labeled reporter antibody (E-Ab), relative to an excess of this reagent in the sample solution. NEEIAs are carried out on microporous membranes coated with a thin, circular area of gold. The gold serves simultaneously as a working electrode and solid phase for immobilized capture anti-protein antibodies. In the assay, analyte protein is incubated concurrently with ...
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J Immunol Methods, Vol. 163, No. 2. (9 August 1993), pp. 161-167
Abstract
The potential of weak competitors to enhance the sensitivity of competitive immunoassays is described. Several triazine derivatives have been analyzed for their use as competitors. Their binding properties were determined using an enzyme-linked immunosorbent assay (ELISA) with a monoclonal antibody specific to triazines. Selected derivatives were immobilized onto the surface of a fibre optic sensor and atrazine was determined in a competitive manner using a fluorescein-labelled antibody. Using the weak binding competitor 11-(4-ethylamino-6-methylthio-s-triazine-2-yl)undecanoic acid (TE11S) the detection limit for atrazine could ...
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Abstract
Creatinine-specific antibodies have been generated and used for highly sensitive and specific immunochemical creatinine determinations. Creatinine was derivatized at N3 and coupled to KLH carrier protein. On the basis of this immunogen, monoclonal antibodies were developed by hybridoma technology. Antibodies from various clones have been characterized with BIAcore 2000 with respect to the dissociation constant and specificity. Antibodies of clone B90-AH5 exhibited the lowest dissociation constant (0.74 microM) and the highest specificity for creatinine and were chosen for the development of ...
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IEEE Sensors Journal, Vol. 6 (Apr 2006), pp. 248-253
Abstract
An ultrasensitive immunodiagnostic readout method based on an electrochemical analysis is presented. Different inorganic quantum dot (QD) nanocrystals (ZnS, CdS, and PbS) are tagged to antibodies for the on-site voltammetric stripping measurements of multiple antigen targets. The multiprotein electrical sensing capability is coupled to the amplification feature of anodic stripping voltammetric transduction and with an efficient magnetic removal (to minimize nonspecific adsorption and cross-reactivity effects). Sandwich-immunoassay formats were performed using model proteins (beta(2)-microglobulin, myoglobin, and human serum albumin). These encoding QD ...
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Electroanalysis, Vol. 17 (Nov 2005), pp. 1901-1918
Abstract
Enzyme immunoassays (EIAs) are currently the predominant analytical technique for the quantitative determination of a broad variety of analytes in clinical, medical, biotechnological, and environmental significance. Although the most common detection methods for EIAs are based on spectroscopic measurements, electrochemical techniques, due to their high sensitivity, selectivity, simplicity and low cost, have emerged as a very attractive alternative to carry out the detection step in this kind of assays. The intention of this review is to cover the progress and development ...
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Abstract
A homogeneous enzyme Immunoassay Is described for the determination of drug antlbodles. The method Is based upon inhlbitlon of the enzyme actlvity of an enzyme-antigen conjugate by the correspondlng antlbody that Is to be measured. The activity Is monitored by amperometrlc detection of fhe rate of NADH oxidation at a platinum electrode. The technique Is Illustrated by uslng the lldocalne-antl-lldocalne system and ylelds callbration curves at nanogram levels of antlbody with absolute sensltlvlty dependent upon the original amount of enzyme-antlgen conjugate. Interferences such as protein adsorption and antl-qulnidine cross-reactivity are shown ...
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Abstract
A homogeneous spectrophotometric EMIT immunoassay kit for the quantitation of theophylline in serum or plasma has been modified to produce a rapid, amperometric immunoassay requiring a 50 microliters whole blood sample. The basis of the detection system for the assay is the electrochemical oxidation of NADH produced by G6PDH-labelled theophylline at a potential of +150 mV vs Ag/AgCl using platinised activated carbon (PACE) electrodes. Comparison of the amperometric whole blood method with the conventional spectrophotometric plasma assay produced a reasonable correlation: ...
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Abstract
Convention immunochemical techniques are often very time consuming. Assay of a sample using, e.g., RIA (radio immuno assay) or ELISA (enzyme linked immunosorbent assay) techniques takes in the order of 2-4 h because of long equilibration times for the antibody and antigen to form the specific antbodyantigen complex [ 1,2] . In recent reports it was demonstrated that when non-equilibrium ELISA was carried out in an enzyme thermistor system assays in a time range of 1 O-l 5 min/assay were made possible 13941. The present paper deals with efforts to make an enzyme ...
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Electroanalysis, Vol. 15, No. 3. (March 2003), pp. 157-167
Abstract
This review discusses current development in electrochemical biosensors for detection of biological warfare agents. This could include bacteria, viruses and toxins that are aerosoled deliberately in air, food or water to spread terrorism and cause disease or death to humans, animals or plants. The rapid and unequivocal detection and identification of biological warfare agents is a major challenge for any government including military, health and other government agents. Reliable, specific characterization and identification of the microorganism from sampling location, either air, ...
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Abstract
The developments in the field of electrochemical immunosensors and immunoassays are reviewed. The enzyme labels suitable for amperometric, potentiometric and conductimetric detection are mentioned. Indirect immunosensors (i.e., that involving enzymatic or electroactive labels) use either heterogeneous or homogeneous formats. Immunoelectrodes are based on conventional electrodes, semiconductor devices are represented by ISFETs and light addressable potentiometric sensors (LAPS). Direct label-free monitoring of immunoreactions is demonstrated on capacitance systems and pulsed detection using polypyrrole-modified electrodes. The approaches to regeneration of sensing surfaces are ...
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Biosens Bioelectron, Vol. 13, No. 2. (February 1998), pp. 173-179
Abstract
An amperometric immunosensor for the detection of the lactate dehydrogenase isoenzyme LD-1 has been developed. Polyclonal antibodies for LD-1 have been covalently immobilised onto a preactivated Immunodyne ABC membrane, reacted with standard LD-1 solutions and placed onto a platinum working electrode polarised at +600 mV vs. Ag/AgCl. Lactate dehydrogenase activity has been measured by detection of the oxidation of NADH at the electrode surface. A calibration curve for LDH in the 0.005-0.12 U range has been obtained with a repeatability of ...
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