The electrochemical detection for horseradish peroxidase-cosubstrate-H(2)O(2) systems was optimized. o-Phenilendiamine, phenol, hydroquinone, pyrocatechol, p-chlorophenol, p-aminophenol and 3,3'-5,5'-tetramethylbenzidine were evaluated as cosubstrates of horseradish peroxidase (HRP) enzyme. Therefore, the reaction time, the addition sequence of the substrates, the cosubstrate:H(2)O(2) ratio and the electrochemical techniques were elected by one-factor optimization assays while the buffer pH, the enzymatic activity and cosubstrate and H(2)O(2) concentrations for each system were selected simultaneously by response surface methodology. Then, the calibration curves for seven horseradish peroxidase-cosubstrate-H(2)O(2) systems were built and the analytic parameters were analyzed. o-Phenilendiamine was selected as the best cosubstrate for the HRP enzyme. For this system the reaction time of 60s, the phosphate buffer pH 6.0, and the concentrations of 2.5×10(-4)molL(-1) o-phenilendiamine and of 1.25×10(-4)molL(-1) H(2)O(2) were chosen as the optimal conditions. In these conditions, the calibration curve of horseradish peroxidase by square wave voltammetry showed a linearity range from 9.5×10(-11) to 1.9×10(-8)molL(-1) and the limit of detection of 3.8×10(-11)molL(-1) with RSD% of 0.03% (n=3).
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http://dx.doi.org/10.1016/j.talanta.2011.11.016 | DOI Listing |
Insect Sci
January 2025
Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, Biological Science Research Center, Southwest University, Chongqing, China.
Respiration is a vital process essential for organism survival, with most terrestrial insects relying on a sophisticated tubular tracheal network. In the current study, a gene with repetitive sequence was identified within the silkworm genome. Designated as BmMuc91C, it contains a dozen repeated motifs "PSSSYGAPX" and "GGYSSGGX" in its sequence.
View Article and Find Full Text PDFAnalyst
January 2025
College of Veterinary Medicine, Institute of Comparative Medicine, Yangzhou University, Yangzhou 225009, China.
The M13 phage carries approximately 5 copies of the pIII protein, each of which is capable of displaying a single-chain variable fragment (scFv) that targets a specific antigen. This feature enables the M13 phage to be widely employed in the construction of scFv libraries, thereby facilitating the identification of antibodies with high specificity and affinity for target antigens. In this study, mice were immunized three times with (strain C50041) to induce diverse antibodies.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
School of Light Industry and Chemical Engineering, Dalian Polytechnic University, Dalian 116034, China. Electronic address:
Accurate, specific, and cost-effective detection of toxic cyanogenic glycosides is crucial for ensuring biological health and food safety. In this study, a novel biosensor based on co-immobilized multi-enzyme system was constructed by artificial antibody-antigen-directed immobilization for the colorimetric detection of amygdalin through a cascade reaction catalyzed by β-glucosidase, glucose oxidase, and horseradish peroxidase. Artificial antibodies and antigens were prepared using catechol and 3,4-dihydroxybenzaldehyde, respectively, to generate mutual affinity recognition ability for enzyme immobilization.
View Article and Find Full Text PDFMikrochim Acta
January 2025
Key Laboratory of Organic Integrated Circuit, Ministry of Education & Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, School of Science, Tianjin University, Tianjin, 300072, China.
A Cr-doped VO nanobelt (Cr/VO) with remarkable peroxidase-like activity was synthesized and coupled with uricase to catalyze the cascade reaction for detection of uric acid. Notably, the affinity of Cr/VO for 3,3',5,5'-tetramethylbenzidine dihydrochloride hydrate (TMB) and hydrogen peroxide (HO) is tenfold and 20-fold higher, respectively, than that of horseradish peroxidase (HRP). The Cr/VO exhibits highly reactive and stable peroxidase activity at temperatures of 20-60 ℃.
View Article and Find Full Text PDFMikrochim Acta
January 2025
College of Medical Technology, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China.
An innovative colorimetric sensing strategy was developed for the detection of glucose by the integration of glucose aptamer, glucose oxidase (GOx), and horseradish peroxidase (HRP), termed aptamer proximal enzyme cascade reactions (APECR). In the presence of glucose, aptamer binding enables GOx to catalyze glucose oxidation into HO efficiently. Subsequently, the adjacent HRP catalyzes the oxidation of the peroxidase substrate, 2,2'-biazobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), utilizing the generated HO, resulting in a distinct color change.
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