Rapid and Large-Scale Synthesis of Chiral and Fluorescent Sulfur Quantum Dots for Intracellular Temperature Monitoring.

The large-scale preparation of fluorescent nanomaterials with laboratory-relevant chemical and optical properties will greatly forward their consumer market applications; however, it still remains challenging. In this work, a universal strategy was developed for the rapid and large-scale synthesis of fluorescent sulfur quantum dots that recently has drawn great attention because of their unique optical characteristics. From the fact that empty 3d orbitals of sulfide species are able to bind with lone-pair π electrons of the heteroatomic groups, many amino-group containing compounds, such as amino acid and polyethylenimine molecules, were exploited to synthesize sulfur quantum dots. This 10 min preparation period endowed sulfur quantum dots with bright blue fluorescence and also chirality. Due to the user-friendly and rapid operation, this strategy can be extended to the large-scale synthesis of sulfur quantum dots with a yield of 16.844 g for one batch of experiment. Moreover, it was found that the sulfur quantum dots exhibited a reversible temperature-dependent luminescent property with a sensitivity of 0.72%/°C, which showed excellent intracellular temperature monitoring capability for inflammation-related disease diagnostics.