Sensing nitrophenols and luminescent ink applications of sulfur quantum dots

Hydrothermal preparation was used to create stable luminous sulfur quantum dots (SQDs), and XRD, XPS, TEM, and FTIR analyses were used to assess their structural and morphological characteristics. With an average size of 5.5 2.0 nm, the SQDs had an S8 monoclinic crystal structure. The SQDs’ 415 nm excitation-independent emission at an excitation wavelength of 342 nm was discovered by optical characterization. Nitrophenols (4- and 2-nitrophenol) having detection limits of 46 and 171 nM, respectively, were successfully detected using high quantum yield (72%) SQDs. Real sample analysis has been conducted with bottled, tap, and river water. The supporting investigation analyzed the fluorescence quenching mechanism and highlighted the probable static quenching phenomenon. SQDs are also an anti-counterfeiting material because of their high luminescence characteristics and have been successfully used as fluorescent ink.