Nonenzymatic H2O2 sensing based on silver nanoparticles capped polyterthiophene/MWCNT nanocomposite

A novel method for highly sensitive H2O2 sensor is proposed using silver nanoparticles (AgNPs) modified oxidized poly-2,2':5',2"-terthiophene 3 p benzoic acid/multi wall carbon nanotube (Ox-pTTBA/MWCNT). The Ox-pTTBA/MWCNT nanocomposite film was prepared via electropolymerization of a TTBA monomer and MWCNT mixture solution, followed by in situ electrooxidation of the pTTBAIMWCNT film. Then, AgNPs were formed on the Ox-pTTBA/MWCNT layer through immersing the freshly prepared Ox-pTTBA/MWCNT electrode in AgNPs solution. The characterization of sensor probe and experimental parameters affecting its activity were investigated employing UV-vis spectroscopy, transition electronic microscopy (TEM), scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS), X-ray photoelectron spectroscopy (XPS), and cyclic voltammetry (CV). The AgNPs/OxpTTBA/MWCNT nanocomposite showed an excellent electrocatalytic activity to H2O2 by significantly increasing the reduction peak current and completely inhibiting the effect of other interfering species. The sensor probe displays a fast response time less than 5s with a linear range from 10 to 260 p,M and detection limit of 0.24 p,M. The sensitive, stable and specific response to H2O2 demonstrates that the present sensor is potentially suitable for monitoring H2O2 concentrations in biological system. The application was conducted for the determination of H2O2 in human urine real samples. (C) 2014 Elsevier B.V. All rights reserved.