Preparation of conductive polyaniline hydrogels co-doped with hydrochloric acid/phytic acid and their application in Ag NPs@PA/GCE biosensor for H₂O₂ detection

Accurate measurement of hydrogen peroxide is of great significance in monitoring human diseases and environmental safety. At present, there are a variety of testing methods, among which the use of electrochemical sensors to accurately measure hydrogen peroxide has gradually become a research hotspot. In this article, phytic acid (PA) with dual functions of doping and cross-linking and HCl with strong ionization capacity was introduced as dopants to co-doping polyaniline, and polyaniline hydrogel with a three-dimensional network structure was prepared. The influence of the HCl/PA co-doping ratio on conductive polyaniline hydrogel (CPAniH) was explored. The synthesis process and mechanism of HCl/PA-CPAniH were analyzed and explained. In addition, the conductivity and mechanism of HCl/PA-CPAniH, as well as the hydrogel characteristics were characterized and studied. A new electrochemical sensor based on polyaniline hydrogel and silver nanoparticles was constructed to detect hydrogen peroxide. The sensor has a good linear relationship, a wide linear range, and a high-detection limit for H2O2. In addition, it also shows that HCl/PA-CPAniH is a good interface material for electrochemical sensors and has a certain application potential.