Abstract
A new analytical strategy based on potentiostatically pretreated graphene/CNT nanocomposite encapsulated Au nanoparticles (AuNPs/PPG/CNT) for the fabrication of H2O2 sensor was developed. The PPG/CNT nanocomposite was obtained through the potentiostatical of G and CNT mixture solution at an applied potential of -1.8V, while AuNPs were immobilized on the PPG/CNT film via the produced active sites in the nanocomposite structure. The morphology and structure of the AuNPs/PPG/CNT nanocomposite were investigated by transmission electronic microscopy (TEM), UV-visible spectroscopy, scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS). The nanocomposite displays intensive electrocatalytic activity towards the reduction of H2O2 by enhancing the cathodic peak current and completely eliminating the interference of other species. The AuNPs/PPG/CNT sensor showed an excellent amperometric response to H2O2 reduction with linear range from 1.0-150 mu M and detection limit of 0.017 mu M. Moreover, the sensor showed good reproducibility as well as anti-interfering ability and long term stability. In addition, the proposed sensor was further applied for analytical determination of H2O2 in human urine real samples.