Synthesis, photoluminescence properties and sensing applications of luminescent sulfur nanodots.

Sulfur nanodots (S-dots), composed of an elemental sulfur core and surface ligands, show unexpected photoluminescence (PL) properties, with the unique features of nontoxicity, hydrophilicity, high stability and easy modification. This review systematically introduces the synthesis methods, characterization, PL mechanisms and some typical applications of S-dots in chemical sensing. As the PL quantum yield (QY) is a key factor to evaluate the performance of luminescent materials, we report the synthesis methods according to the achievement in the promotion of PL QY. The PL mechanisms of S-dots are discussed from the view of the effects of the elemental sulfur core and passivated ligands on the PL QY and emission color. The design principle of analytical methods for various target molecules using S-dots is introduced. We end this review with the conclusions and some challenges in this field, which is expected to provide some clues for researchers in this field.