Amperometric Microcavity Electrode for Hydrogen Peroxide Based on Sulfhydryl-Containing Multiwalled Carbon Nanotube/Silver Nanoparticles

A novel amperometric hydrogen peroxide microcavity electrode (MCE) was fabricated based on sulfhydryl-containing multiwalled carbon nanotubes/silver nanoparticle (MWNTs-SH/AgNPs) nanohybrids. Due to the synergistic amplification property of the MWNTs-SH/AgNPs, The modified MCE (MWNTs-SH/AgNPs/MCE) shows a dramatic electrocatalytic effect on the reduction of hydrogen peroxide. The results showed that MWNTs-SH/AgNPs/MCE exhibited linear dependence on H2O2 concentration in the range between 1.0 × 10−5 and 1.1 × 10−3 mol/L with a correlation coefficient of −0.9996. The detection limit (signal-to-noise ratio S/N = 3) was 1.7 × 10−6 mol/L. The response in the current to coexisting interferences on the MCE surface is almost negligible. This novel microsensor has high potential in detection of hydrogen peroxide in biological environments.