Electrosynthesis of gold nanoparticles/porous GaN electrode for non-enzymatic hydrogen peroxide detection

Here we report the electrodeposition of gold nanoparticles (AuNPs) onto porous GaN electrode obtained by photoelectrochemical etching planar GaN to fabricate a non-enzymatic hydrogen peroxide (H2O2) sensor. SEM images revealed porous GaN has uniformly high-porosity structure and the diameter of AuNPs is 5-16 nm. The AuNPs/porous GaN electrode exhibited good electrocatalytic activity toward the reduction of H2O2 and performed as amperometric sensor for the detection of H2O2. The AuNPs/porous GaN electrode showed linear amperometric responses for H2O2 in the concentration range from 10 to 100 mu M with the sensitivity of 281.5 mu A mM(-1). The limit of detection (LOD) is 2 mu M with a signal-to-noise ratio of 3. In addition, the AuNPs/porous GaN electrode exhibited good repeatability, reproducibility, selectivity and long-term stability for H2O2 detection, in the meanwhile, AuNPs showed excellent adhesive capacity to the porous GaN electrode, which was tested by continually sonicating the AuNPs/porous GaN electrode for 3 h. Above results demonstrated this simply prepared H2O2 sensor has good practicability and is promising to measure the analyte in practical applications. (C) 2016 Elsevier B.V. All rights reserved.