Group 6 Layered Transition-Metal Dichalcogenides in Lab-on-a-Chip Devices: 1T-Phase WS₂ for Microfluidics Non-Enzymatic Detection of Hydrogen Peroxide

Two-dimensional (2D) layered transition-metal dichalcogenides (TMDs) have been placed in the spotlight for their advantageous properties for catalytic and sensing applications. However, little work is done to explore and exploit them in enhancing the performance of analytical lab-on-a-chip (LOC) devices. In this work, we demonstrate a simple, sensitive, and low-cost fabrication of electrochemical LOC microfluidic devices to be used for enzymatic detection. We integrated four t-BuLi exfoliated, group 6 TMD materials (MoS₂, MoSe₂, WS₂, and WSe₂) within the LOC devices by the drop-casting method and compared their performance for H₂O₂ detection. The 1T-phase WS₂-based LOC device outperformed the rest of the TMD materials and exhibited a wide range of linear response (20 nM to 20 μM and 100 μM to 2 mM), low detection limit (2.0 nM), and good selectivity for applications in real sample analysis. This work may facilitate the expanded use of electrochemical LOC microfluidics, with its easier integrability, for applications in the field of biodiagnostics and sensing.