Highly sensitive platinum nanoparticles-embedded porous graphene sensor for monitoring ROS from living cells upon oxidative stress

Real-time monitoring reactive oxygen species (ROS) released from living cells is important in both physiological and pathological contexts. The excessive amount of ROS accumulation in cells could lead to a series of cell damage and cause aging and disease. Here we present design, fabrication, and successful testing of a highly sensitive electrochemical hydrogen peroxide sensor based on a three-dimensional (3D) platinum nanoparticles (PtNPs) decorated porous graphene composite. Scanning electron microscopy (SEM) investigations indicate that PtNPs were embedded into porous graphene (PGN), something that was rarely reported. With the help of the excellent catalytic activity of PtNPs and unique porous structure in combination with inherent properties of graphene, the PtNPs/PGN based sensor presents efficient electrochemical performance for H2O2 sensing with a detection limit of 0.02 nM, the lowest detection limit achieved in nonenzymatic electrochemical sensors so far, which guarantees the possibility of sensitive and reliable detection of H2O2 release from living cells. This work opens a new avenue for direct preparation of metal nanoparticle-embedded porous graphene composite. More importantly, the presented sensors can be successfully used for monitoring changes of H2O2 levels upon different stimuli and collecting kinetic information on cellular ROS release, which provides more opportunities to study its cellular biochemistry. (C) 2018 Elsevier B.V. All rights reserved.