Sequential-Injection Amperometric Determination of Glucose, Insulin, Cholesterol, and Uric Acid on Electrodes Modified by Nickel and Cobalt Particles

Abstract

© 2020, Pleiades Publishing, Ltd. Abstract: It was found that nickel particles electrodeposited on the surface of planar carbon electrodes (PE; Ni–PE) exhibit catalytic activity in the electrooxidation of glucose, insulin, and cholesterol (CS) in alkaline media, and cobalt particles (Co–PE), in the oxidation of CS, insulin, and uric acid (UA) in neutral media. In recording an analytical signal in a system of sequential-injection analysis with amperometric detection, the bilogarithmic dependence of current on the analyte concentration on a Ni–PE electrode is linear in the range from 5 × 10–6 to 5 × 10–2 M for glucose, from 1 × 10–6 to 1 × 10–4 M for insulin, and from 5 × 10–6 to 5 × 10–3 M for CS. On the Co–PE electrode, it is linear from 5 × 10–7 to 5 × 10–3 M for CS, from 5 × 10–8 to 5 × 10–4 M for insulin, and from 5 × 10–8 to 5 × 10–3 M for UA. It is shown that the use of a two-detector system and modified double planar electrodes ensures the selective determination of the studied biologically active compounds in blood serum.