Optical determination of hydrogen peroxide by exploiting the peroxidase-like activity of AgVO3 nanobelts

AgVO3 nanobelts (typically 0.5 to 5 μm in length; 100 nm in width) are demonstrated for the first time to possess intrinsic peroxidase-like activity. The substrate 3,3′,5,5′-tetramethylbenzidine is converted to a blue dye (with an absorbance maximum at 652 nm) in the presence of H2O2. Kinetic analysis indicates that the catalytic reaction follows a ping-pong mechanism. Moreover, a possible photocatalytic mechanism is proposed based on active species trapping experiments, demonstrating that hydroxy radicals play major roles in this system. This feature of the nanobelts is used for quantitative kinetic determination of H2O2. The assay has a 5 μM detection limit and a detection range from 0.075 to 0.5 mM. Other attractive features include a good chemical stability and high specificity of the nanobelts, simplicity of the assay, and the good reproducibility of the synthesis of the material.