Nanoscale Chirality in Carbon Quantum Dots Enables Enantioselective Fluorescence Recognition of D-Penicillamine

We successfully synthesized a chiral probe using a one-pot hydrothermal method involving L-/D-arginine and citric acid. The chiral carbon quantum dots (CQDs) were comprehensively characterized by various techniques such as FTIR, NMR, XPS, TEM, HRTEM, FESEM, and UV-vis. Fluorescence and circular dichroism were conducted to demonstrate that chiral ligands anchored at the nanoscale. To the best of our knowledge, this study represents the first report of arginine-derived chiral CQDs for enantioselective fluorescence recognition of D-penicillamine (D-PA). The results demonstrated an interaction between L-/D-Arg-CQDs and D-PA, evident from the significant reduction in emission intensity and quenching upon their introduction. Furthermore, experimental investigations focused on examining the enantioselective interaction behavior between D-PA and both L-Arg-CQDs and D-Arg-CQDs. It was found that both L-/D-Arg-CQDs exhibited a linear response over a concentration range of 50-10,000 nM of D-PA. Notably, the relative photoluminescence intensities of the chiral probes in relation to D-PA revealed that L-Arg-CQDs displayed a more pronounced interaction, leading to a steeper decline in emission compared to D-Arg-CQDs. In conclusion, the potential of chiral CQDs in enantioselective detection offers significant benefits for the pharmaceutical industry and related fields, where ensuring the safety and efficacy of pharmaceutical products is of utmost importance.