Biocompatible PB/Ti3C2 hybrid nanocomposites for the non-enzymatic electrochemical detection of H2O2 released from living cells

The rapid and accurate detection of H2O2 levels in living cells has important significance in the early-diagnosis of many diseases. In this paper, a non-enzymatic electrochemical biosensor based on Prussian blue (PB) nanoparticles (NPs) intercalated Ti3C2 nanosheets (PB NPs/Ti3C2) was fabricated as a platform for detecting H2O2. Physico-chemical characterizations revealed the optimized morphology and enlarged surface area of PB NPs/Ti3C2. When applied to determine H2O2 at the optimal potential, wide linear response in the ranges of 0.6 μM–63.6 μM and 63.6 μM–254 μM, a low limit of detection (0.20 μM), satisfactory stability and anti-interference ability were obtained at PB/Ti3C2/GCE for the synergistic effect between PB and Ti3C2 on the structure optimization and performance complementation. Moreover, the prepared PB/Ti3C2 showed negligible cytotoxicity to normal fibroblast cells at all tested time points and concentrations, validating its potential application in living cell concerned fields. For proof of concept, the proposed PB/Ti3C2/GCE realized the real-time and in-situ detection of H2O2 secreted from living HeLa cells. Overall, the biocompatible PB/Ti3C2 sensing interface with a hierarchical structure would be a competitive candidate for H2O2 monitoring in biological samples or cellular investigation.