Electrochemical tracking hydrogen peroxide secretion in live cells based on autocatalytic oxidation reaction of silver nanoparticles

•An electrochemical method for tracking H2O2 secretion in live cells is established.•A limit of detection as low as 0.5 μM is achieved.•Mechanism of autocatalytic oxidation reaction of silver nanoparticles is discussed.

In this work, stable silver nanoparticles (AgNPs) are prepared by borohydride reduction. Autocatalytic oxidation reaction of AgNPs in the presence of hydrogen peroxide (H2O2) is investigated. Sharp silver stripping peak in linear sweep voltammogram is used to reflect H2O2 concentration and the detection limit of 0.5 μM is achieved. We have also explored the application of the simply prepared AgNP modified electrode for electrochemical tracking H2O2 secretion in live cells. This facile strategy shows excellent sensitivity, stability and has great potential use in physiological and pathological applications.