Corona Discharge‐Assisted Formation of Luminescent Mos ₂ Nanosheets and Their Application as a Turn‐On Sensor for Lead (II) Ions

Abstract The thin layers of MoS 2 nanosheets possess unique optoelectronic properties. Consequently, numerous methods have been explored to fabricate uniform MoS 2 nanosheets, including chemical vapor deposition, mechanical exfoliation, and liquid‐phase exfoliation. Here, we report an effective approach for synthesizing few‐layer MoS 2 nanosheets by a corona discharge set‐up. The number of layers and size of MoS 2 nanosheets were validated using transmission electron microscopy (TEM), atomic force microscopy (AFM), and Raman spectroscopy. The nanosheets exhibit luminescence, and a simple, fluorescent‐based sensor for the detection of lead (II) is demonstrated that uses lead (II)‐induced fluorescence enhancement of MoS 2 nanosheets. The sensor has a dynamic range of 0.5−9.0 µmol/L toward Pb 2+ detection, along with selectivity for Pb 2+ in the presence of other metal ions and common organic molecules. The sensor exhibits excellent repeatability and reproducibility, making it an ideal candidate for practical applications in environmental monitoring. Hence this study not only paves the way for new methods to be developed in the future for producing fluorescent multilayer transition metal dichalcogenides with high quantum yields but also offers a flexible and long‐lasting sensing platform.