Low-potential determination of hydrogen peroxide, uric acid and uricase based on highly selective oxidation of p-hydroxyphenylboronic acid by hydrogen peroxide

A new strategy for the electrochemical determination of hydrogen peroxide (H2O2), uric acid (UA), and urate oxidase (UOx) has been developed. The strategy is based on the indirect electrochemical detection of hydrogen peroxide through detecting p-hydroxyphenol generated from the selective oxidation of p-hydroxyphenylboronic acid by hydrogen peroxide. As it is easy to detect p-hydroxyphenol with excellent selectivity at low potential, the sensors display satisfactory analytical performance, such as wide dynamic range, high sensitivity, and good selectivity. The sensor exhibits a linear response over the range of 1 μM to 1 mM, 1–500 μM, and 0.005–0.1 U/mL with the detection limits of 0.31 μM, 0.3 μM, and 0.005 U/mL for hydrogen peroxide, UA, and UOx, respectively. Furthermore, the sensor exhibited excellent recoveries for the determination of UA in serum samples. The detection scheme is very simple, and can be readily extended to detect other oxidases and their substrates.