Facilely proposed PtCu-rGO bimetallic nanocomposites modified carbon fibers microelectrodes for detecting hydrogen peroxide released from living cells

Hydrogen peroxide (H 2 O 2 ) is an important biomarker for recognition of multiple diseases, the construction of nonenzymatic miniaturized sensors that capable to real-time monitor H 2 O 2 is tremendously significant. Here, we developed a high-performance microelectrode based on carbon fiber via a facile stepwise electrodeposition method, which could realize the high-sensitivity detection of the target H 2 O 2 . Carbon fiber was decorated by reduced graphene oxide supported PtCu bimetallic cluster nanocomposite (PtCu-rGO), in which rGO as catalyst support had a thin layer, which could realize the uniform loading of the other material. Meanwhile, in virtue of the low cost and synergistic effect, PtCu bimetallic cluster nanoparticles exhibited great potential in electrocatalytic of H 2 O 2 . The PtCu-rGO modified microelectrode displayed outstanding electrochemical behavior to H 2 O 2 sensing, including a broad working range of 5 μM-1270 μM (R 2  = 0.991), 1270 μM-3920 μM (R 2  = 0.998) with high sensitivity (15079.9 μA mM -1 cm −2 , 5–1270 μM; 10319.8 μA mM −1 cm −2 , 1270–3920 μM), an appreciable detection limit of 0.60 μM, as well as good selectivity, reproducibility and stability. Additionally, this easy-to-interpret sensor enabled real-time monitoring of H 2 O 2 generated from living cells and could further recognize cancer cells and normal cells. This newly proposed microsensor could be a promising tool for clinic diagnosis.