Dual-functional carbon dots based on sorbic acid application in bimodal probing and white LEDs.

This study successfully synthesized bifunctional carbon dots (CDs) using sorbic acid as a single precursor, endowing the material with dual sensing-photoelectronic properties. When employed as probes, these CDs exhibit rare bimodal characteristics: they demonstrate not only superior sensing performance in down-conversion photoluminescence (DPL) mode but also exceptional detection capability in up-conversion photoluminescence (UPL) mode. Experimental results revealed linear correlations between acetonitrile content and fluorescence intensities in acetone/acetonitrile mixtures, with determination coefficients of 0.9583 (DPL) and 0.9103 (UPL). Notably, the modified sorbic acid-derived CDs overcome the prevalent aggregation-caused quenching effect in conventional solid-state CDs, achieving a remarkable solid-state external quantum yield of 32 %. This breakthrough enables their direct integration into white LEDs without requiring complex post-processing procedures. The research ultimately accomplishes the dual application of single-precursor-derived bifunctional CDs in both bimodal probing and optoelectronic devices.