High‐Pressure Spray Exfoliation of Multifunctional MoS₂ Nanodots: Biocompatibility and Bioimaging

Molybdenum disulfide (MoS 2 ) nanodots are of growing interest due to their remarkable optical, electronic, and biological properties, making them suitable for diverse applications such as energy storage, catalysis, sensing, and biomedicine. In this work, we introduce a green and scalable synthesis method using high‐pressure spray exfoliation (HPSE) to produce MoS 2 nanodots from bulk MoS 2 . The exfoliation is driven by high pressure and intense shear forces within the spray nozzle, resulting in nanoscale dots. Characterization through transmission electron microscopy, atomic force microscopy, and X‐ray diffraction confirms the successful synthesis of well‐dispersed nanodots. Spectroscopic analyses (XPS and FTIR) indicate that the chemical structure of MoS 2 is preserved, with edge oxidation of Mo and S atoms. The method yields nanodots at a concentration of 0.1 mg/mL and a 0.1% yield. Optical studies reveal both blueshift and redshift in fluorescence emission, indicating altered photoluminescent behavior due to quantum confinement and edge‐state effects. Importantly, cytocompatibility and hemolysis assays confirm the nanodots are biocompatible. This is supported by fluorescence imaging of L929 cells, where internalized MoS 2 nanodots emit blue fluorescence, highlighting their potential for biomedical imaging.