A novel nonenzymatic hydrogen peroxide sensor based on silver nanoparticles and ionic liquid functionalized multiwalled carbon nanotube composite modified electrode

摘要

A novel hydrogen peroxide (H_2O_2) sensor was fabricated by electrodepositing Ag nanoparticles (NPs) on a glassy carbon electrode (GCE) modified with ionic liquid functionalized multiwalled carbon nanotube (MWCNTs-IL) composites. The AgNPs/MWCNTs-IL composite was characterized by different methods including scanning electron microscopy (SEM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The constructed electrode exhibited good catalytic activity toward the reduction of H_2O_2, and obtained a linear response to logarithm of the H_2O_2 concentrations ranging from 1.2 × 10~(-8) to 4.8 × 10~(-6) M with a limit of detection (LOD) of 3.9 × 10~(-9) M. Moreover, it can be applied to real samples analysis. The excellent performance of hydrogen peroxide sensor were ascribed to the MWCNTs-IL composites being used as effective load matrix for the deposition of AgNPs and the synergistic amplification effect of the two kinds of nanomaterials - AgNPs and MWCNTs. Therefore, the catalytic mechanism of the constructed sensor was proposed. AgNPs dispersed on MWCNTs-IL were used as the catalyst for the H_2O_2 into O_2, and the generated oxygen transported the electrode surrounding where it was detected by reduction on the electrode.