A Novel MXene@MOF@Pt NPs-Based Enzyme-Free Electrochemical Sensor for highly Sensitive Detection of Hydrogen Peroxide Released from Living Cells

Rapid and accurate detection of hydrogen peroxide (H 2 O 2 ), an important reactive oxygen species (ROS) released from living cells, is of great significance for early diagnosis of tumors. Here, a high sensitive enzyme-free electrochemical sensor for the detection of H 2 O 2 released from living cells was constructed based on MXene@ZIF-8@Pt NPs nanocomposites. Through the characterization of physical and chemical properties, it was observed that Pt NPs with excellent catalytic activity were uniformly supported on MXene@ZIF-8, which exhibited excellent conductivity and large specific surface area. Thanks to the significantly enhanced catalytic activity derived from the successful integration of MXene, ZIF-8 and Pt NPs, under the optimal conditions, the sensing platform based on MXene@ZIF-8@Pt NPs exhibited a wide linear range from 355.4 nM to 21.75 mM, with a limit of detection as low as 120.9 nM, while showing satisfactory reproducibility and selectivity. Furthermore, the developed electrochemical sensor enables real-time monitoring of H 2 O 2 released from living Hela cells under N-formylmethionyl-leucyl-phenylalanine stimulation. Overall, the MXene@ZIF-8@Pt NPs developed in this article will become a promising candidate in monitoring physiological processes.