Development of chemically modified carbon paste electrodes with transition metal complexes anchored on silica gel

Abstract The chemically modified silica gel with 3-(2-aminoethyl)aminopropyl]trimethoxysilane groups and p -aminobenzoic acid was used to immobilize the nickel (II) and cobalt(II) metallic ions complex initially. These materials were incorporated into a carbon paste electrode and its electrochemical properties were investigated. However, for dopamine and B 6 vitamin solution, an enhancement of the anodic peak current was detected due to electrocatalytic oxidation. The electrodes presented the same response for at least 150 successive measurements, with a good repeatability. The modified electrodes are very stable and reproducible. The sensors were applied for dopamine and B 6 vitamin determination in pharmaceutical preparation with success.