High-yield exfoliation of ultrathin two-dimensional ternary chalcogenide nanosheets for highly sensitive and selective fluorescence DNA sensors

High-yield preparation of ultrathin two-dimensional (2D) nanosheets is of great importance for the further exploration of their unique properties and promising applications. Herein, for the first time, the high-yield and scalable production of ultrathin 2D ternary chalcogenide nanosheets, including Ta₂NiS₅ and Ta₂NiSe₅, in solution is achieved by exfoliating their layered microflakes. The size of resulting Ta₂NiS₅ and Ta₂NiS₅ nanosheets ranges from tens of nanometers to few micrometers. Importantly, the production yield of single-layer Ta₂NiS₅ nanosheets is very high, ca. 86%. As a proof-of-concept application, the single-layer Ta₂NiS₅ is used as a novel fluorescence sensing platform for the detection of DNA with excellent selectivity and high sensitivity (with detection limit of 50 pM). These solution-processable, high-yield, large-amount ternary chalcogenide nanosheets may also have potential applications in electrocatalysis, supercapacitors, and electronic devices.