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.