Self-quenching-resistant fluorescent tunable sulfur quantum dots

Fluorescence-tunable sulfur quantum dots (SQDs) were obtained by an assembly-fission process and assisted etching with H2O2. The morphological and structural characterization indicated that the obtained SQDs possess excellent dispersion, high water solubility and abundant surface functional groups, which is beneficial to its further application. In the Gaussian software, the electron cloud density distribution around the entire molecular structure is simulated and the density generalization calculations confirms that the main reason for the red shift of emission is the synergistic effect of SQDs size and surface states. Moreover, blue fluorescent SQDs (B-SQDs) showed high sensitivity and specific selectivity toward berberine hydrochloride with detection limits as low as 0.24 nM, and have been successfully used for water sample and actual drug detection. It is noteworthy that the solid-state luminescence properties of SQDs are mainly attributed to the adsorption of chain PEG on the surface of SQDs. By mixing SQDs with epoxy resin, dual-color fluorescent films were prepared and used as the fluorescence conversion layer to manufacture high-performance light-emitting diodes. The CIE (Commission Internationale d ' Eclairage) coordinates of WLED is (0.27,0.29), CCT (Correlated color temperature) is 5793 K and CRI (Color rendering index) is 85.2. Moreover, the prepared SQDs are highly fluorescent and enable latent fingerprint imaging for identity recognition. This work has advanced the development of SQDs for analytical sensing, optical devices, and fingerprint imaging.