Ag/polyaniline nanocomposites: Synthesize, characterization, and application to the detection of dopamine and tyrosine

In this research, Ag/Polyaniline (PANI) nanocomposites were synthesized successfully by the chemical oxidative polymerization of aniline in the presence of 4-aminothiophenol (4-ATP) capped colloidal Ag nanoparticles (NPs). First, Ag colloidal NPs were prepared by borohydride reduction of AgNO3 in the presence of 4-ATP as a stabilizer. Then, polymerization of aniline in the presence of Ag NPs was carried out by ammonium persulfate as an oxidant at room temperature. TEM, SEM, XRD, FTIR, EDX, TGA, and UV-vis studies were done for the morphological, structural, thermal, and optical characterization of the Ag/PANI nanocomposite. Furthermore, Ag/PANI nanocomposites were immobilized on the surface of a glassy carbon electrode (GCE) and electroactivity behavior was investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The obtained Ag/PANI modified GCE showed high catalytic activity for the oxidation of dopamine (DA) and tyrosine (Tyr). The peak current of differential pulse voltammograms of DA and Tyr increased linearly with their concentration in the ranges of 2.17-5.74 M Tyr and 18.5-72.2 M DA. The detection limits for DA and Tyr were 0.002 and 0.009 M, respectively. (c) 2013 Wiley Periodicals, Inc.