Detection of cellular H2O2 in living cells based on horseradish peroxidase at the interface of Au nanoparticles decorated graphene oxide

A biosensor was developed for amperometric detection of H2O2 based on immobilization of HRP at the interface of GO decorated with AuNPs. It was then used to efficiently detect the flux of H2O2 from living cells, indicating higher level of H2O2 in cancer cells than normal cells. •A sensing platform was developed by assembling HRP on AuNPs decorated GO interface.•The modified electrode exhibited remarkable performance for H2O2 detection.•The biosensor could be used to detect the cellular H2O2 released from living cells. An interface of graphene oxide (GO) decorated with Au nanoparticles (AuNPs) was fabricated to immobilize horseradish peroxidase (HRP) for amperometric detection of H2O2. Due to the biocompatibility of AuNPs and large surface area of GO, the immobilized HRP could retain its inherent bioactivity and exhibited remarkable performance for H2O2 detection. These remarkable analytical advantages such as low detection limit, wide linear range and fast response time could fulfill the requirement of real-time measurement of cellular H2O2 in living cells. Interestingly, results indicated that the levels of intracellular H2O2 depended on the types of cells. This approach provided a simple and effective platform for sensing H2O2 inside biological cells and could be used for the study of H2O2-involved dynamic biological processes.