A selective dopamine biosensor based on AgCl@polyaniline core–shell nanocomposites

Silver chloride@polyaniline (PANI) core–shell (AgCl@PANI) nanocomposites were synthesized in the presence of polyvinylpyrrolidone (PVP). The obtained AgCl@PANI nanocomposites could be easily dispersed in aqueous media, which overcame the processible issues of PANI. Moreover, the nanocomposites showed excellent electrochemical behavior at pH neutral environment, and had inhibitive effect on oxidation of ascorbic acid. Fourier transform infrared spectrophotometry (FTIR) confirmed the existence of PVP in the nanocomposites. The C = O group of PVP is easy to form hydrogen bonding with the hydroxyl group of ascorbic acid, which can prevent ascorbic acid from oxidization. A selective dopamine biosensor was constructed based on the particular characteristic of the AgCl@PANI nanocomposites by the simple drop-coating. The biosensor could detect dopamine at its very low concentration in the presence of 5000 time concentration of ascorbic acid at neutral environment.