New electrochemical assay of alkaline phosphatase using ascorbic acid 2-phosphate and its application to enzyme immunoassay

Self‐Assembled Redox System for Bioelectrocatalytic Assay of L‐Ascorbylphosphate and Alkaline Phosphatase Activity

“…For ALP, the apparent detection limit (3Â standard deviation of the blank measurements) was estimated to be 2 pM. This value is in close agreement with the parameter reported in paper [17].…”

“…AAP oxidation process was adsorption-controlled and occured at very high, 0.94 -2.0 V (vs. Ag/AgCl electrode) potentials of working electrode. Kokado et al reported the development of a flow injection analysis for alkaline phosphatase (ALP) using AAP as a substrate that is detected electrochemically at glassy carbon electrode at 0.4 V (vs. SCE) after hydrolysis [17]. The detection limit of ALP was 1.6 pM.…”

An electrochemical amplification immunoassay using biocatalytic metal deposition coupled with anodic stripping voltammetric detection

“…After the layer of immunocomplex (human IgG 1 g mL −1 ) was formed on the electrode surface, the gold electrode was immersed into EB solution containing AA-p and AgNO 3 for silver deposition. The alkaline phosphatase converts AA-p to ascorbic acid, a reducing reagent that reduces silver ions, forming a metallic silver layer on the electrode under the optimum pH value 9.0 [21]. Since the half-wave potential of ascorbic acid is 0.39 V versus NHE, and that of Ag + /Ag is 0.7995 V, so the ascorbic acid in alkaline solution spontaneously reduces silver ions in solution.…”

Successively amplified electrochemical immunoassay based on biocatalytic deposition of silver nanoparticles and silver enhancement

“…As one of the most important enzymatic labels for ELISA due to its high turnover number and broad substrate specificity, alkaline phosphatase (ALP) was adopted to be the indicator for the analyte by using ascorbic acid 2-phosphate (AA-p) as substrate, which has been proved feasible for electrochemical detection (Kokado et al, 2000). After the sandwich type immunocomplex was formed, the ALP bound on the polystyrene microwells converted the AA-p into ascorbic acid.…”