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3‐Indoxyl Phosphate: an Alkaline Phosphatase Substrate for Enzyme Immunoassays with Voltammetric Detection
Author(s) -
FernándezSánchez César,
CostaGarcı´a Agusťín
Publication year - 1998
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/(sici)1521-4109(199804)10:4<249::aid-elan249>3.0.co;2-c
Subject(s) - chemistry , substrate (aquarium) , cyclic voltammetry , alkaline phosphatase , adsorption , electrode , voltammetry , phosphate , electrochemistry , inorganic chemistry , carbon paste electrode , detection limit , nuclear chemistry , chromatography , enzyme , organic chemistry , oceanography , geology
The voltammetric detection of the indigo blue generated when 3‐indoxyl phosphate is used as the substrate for the alkaline phosphatase enzyme has been studied. This molecule undergoes a reversible process on a carbon paste electrode at 0.0 V in 0.1 M HClO 4 and at around −0.4 V in 0.1 M Tris buffer. Moreover, it is strongly adsorbed on the electrode surface. For these reasons, a comparative study of the electrochemical behavior of both, substrate and product, was carried out by cyclic voltammetry and alternating current voltammetry. At the same time, the adsorption of an alkaline phosphatase labeled immunoglobulin G on a carbon paste electrode has been explored by these two techniques, using 3‐indoxyl phosphate as the enzymatic substrate.