Efficient electrochemical biosensing of hydrogen peroxide on bimetallic MoWS nanoflowers.

Two-dimensional transition-metal dichalcogenides can serve as emerging biosensing platforms after rational structural optimization. Herein, we develop a series of MoWS and investigate the composition-dependent sensing of hydrogen peroxide (HO). Among them, the MoWS affords high sensitivity (1290 μA mM cm), good selectivity, and wide applicable concentration range (4 × 10-1.0 × 10 μM). As indicated by theoretical investigations, such prominent performance stems from the bimetallic electronic configurations and the enhanced *OH binding on surface. Moreover, the MoWS is capable of monitoring trace amounts of HO released from normal cells and various cancer cells, which provides efficient cell detection for clinical diagnosis. In addition, the composition-dependence, as a result of electronic modulation on MoWS surface, is further evidenced on electrocatalytic hydrogen evolution reaction, which highlights the promise in sensing and electrocatalysis that share similar electrochemical fundamentals.