Publications (2)2.4 Total impact
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ABSTRACT: A cyanidin-based horseradish peroxidase (HRP)-catalyzed reaction system was established in this work. In B-R buffer solutions (pH 6.8), a UV-visible absorbance peak of cyanidin (CAG) at 540 nm (A p1) appeared. After the oxidation reaction of CAG catalyzed by HRP in the presence of H2O2, a significant absorbance peak at 482 nm (A p2) occurred. The ratio R(A P2/A P1) was proportional to the HRP concentration. The application of CAG in the enzyme-linked immunosensing assays was investigated using food and mouth disease virus antigen (FMDVAg) as a model analyte. In sandwich immunoreaction, the analyte FMDVAg and food and mouth disease virus antibody (FMDVAb)-modified magnetic nanoparticles bound the supported conconvalina (Con A) bound with HRP-FMDVAb. After de-absorbing and separating, the HRP-FMDVAb-FMDVAg-FMDVAb-magnetic nanoparticles complexes were subject to enzymatic reaction and UV-visible absorbance measurements. The HRP moiety of the immunoreaction complexes can catalyze the oxidation reaction of CAG by H2O2, and the substrate CAG is converted to products. Based on this principle, a sandwich assay model has been employed to determine FMDVAg in rabbit serum samples with the aid of FMDVAb-Fe3O4 magnetic nanoparticles. The linear range of the FMDVAg determination is 1.5×10−8−2.7×10−6 g/mL with the relatively standard deviation of 3.7% (n = 11). The detection limit is 3.1×10−9 g/mL. Additional advantages of the typical substrate such as OPD, OAP and TMB are good water-solubility and stability.
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ABSTRACT: The properties of resveratrol (3′, 4′, 5-trihydroxystlbene, RST) were for the first time evaluated as a potential substrate for horseradish peroxidase (HRP)-catalyzed fluorogenic reaction. The properties of RST for use as fluorogenic substrates for HRP and its application in immunoassays were compared with commercially available substrates such as p-hydroxyphenylpropionic acid (pHPPA), chavicol and Amplex red by a fluoroimmunosensing method in the use of Schistosomia japonicum antibody (SjAb) as a model analyte. The fluoroimmunosensing device was constructed by dispersing Schistosomia japonicum antigen (SjAg), nano-Ag/SiO2 particles and sol-gel at low temperature. In pH 5.8 Britton-Robinson buffer (B-R), HRP-SjAb conjugates can catalyze the polymerization reaction of RST by H2O2 forming fluorescent dimmers. The increase of the fluorescence intensity of the dimmers product at emission of 462 nm (excitation: 315 nm) is proportional to the concentration of HRP-SjAb binding to the SjAg entrapped in the nano-Ag/SiO2 particles-sol-gel matrix. A competitive binding assay has been used to determine SjAb in rabbit serum with the aid of SjAb labeled with HRP. Substrate RST showed comparable ability for HRP detection and its enzyme-linked immunosensing reaction system, in a linear detection ranging of 1.5×10−6–7.3×10−4 g/L and with a detection limit of 1.5×10−6 g/L. The immobilized biocomposites surface could be regenerated by simply polishing with an alumina paper, with an excellent reproducibility (RSD = 4.7%). The proposed method has been successfully used for analysis of the rabbit serum sample with satisfactory results.
Changsha University of Science and TechnologyCh’ang-sha-shih, Hunan, China