1T‐Phase WS₂ Protein‐Based Biosensor

Metallic 1T‐phase transition metal dichalcogenides have been recognized for their desirable properties like high surface‐to‐volume ratio, high conductivity, and capacitive behavior, making them outstanding for catalytic and sensing applications. Herein, a hydrogen peroxide (H₂O₂) biosensor is constructed by the immobilization of hemoglobin (Hb) on 1T‐phase WS₂ (1T‐WS₂) sheets, and entrapment by glutaraldehyde. 1T‐WS₂ not only displays electrocatalytic activity toward the reduction of H₂O₂ but also provides a high surface‐to‐volume ratio and conductive platform for the immobilization of Hb and facilitation of its electron transfer to the electrode surface. The advantageous role of 1T‐phase WS₂ is further demonstrated for the construction of a heme‐based H₂O₂ biosensor compared to its 1T‐phase MoS_2, MoSe₂, and WSe₂ counterparts. Synergistic interactions between 1T‐WS₂ and Hb result in a H₂O₂ biosensor with high analytical performance in terms of wide range, sensitivity, selectivity, reproducibility, repeatability, and stability. These findings have profound impact in the research fields of electrochemical sensing and biodiagnostics.