K. Jiao, Wei Sun, Shusheng Zhang
May 18, 2000
Citations
1
Influential Citations
36
Citations
Journal
Analytica Chimica Acta
Abstract
Abstract p -Phenylenediamine (PPD), a new substrate for peroxidase-mediated voltammetric enzyme immunoassay, was investigated by electrochemical methods and used for the detection of plant virus. The product of PPD oxidation with H 2 O 2 catalyzed by horseradish peroxidase (HRP) is 2,5-diamino- N , N ′-di-(4-aminophenyl)-2,5-cyclohexadiene-1,4-diimine in pH 3.0–7.0 Britton–Robinson (B–R) buffer solution, which has a sensitive voltammetric peak at the potential of −0.97 V (versus Ag/AgCl) in pH 10.0 B–R buffer solution. By using this voltammetric peak current, HRP can be measured with a detection limit of 0.95 mU l −1 and a linear range of 1.75–750 mU l −1 . Combined this new PPD–H 2 O 2 –HRP voltammetric enzyme-linked immunoassay system with direct antigen coating (DAC) enzyme-linked immunosorbent assay (ELISA), cucumber mosaic virus (CMV) can be detected as low as 0.5 ng ml −1 , which is 10 times lower than that of the conventional spectrophotometric o -phenylenediamine (OPD) ELISA method. The processes of the enzyme-catalyzed reaction and the electro-reduction of the product of the enzyme-catalyzed reaction have been investigated.