ACS Applied Bio Materials, Journal Year: 2024, Volume and Issue: unknown
Published: Dec. 12, 2024
Blue-emissive nitrogen-doped chiral carbon dots (d-NCD230 and l-NCD230) exhibiting antipodal chiroptical activity, synthesized from the thermal pyrolysis of citric acid d/l-aspartic in 1:2 molar ratios, have been explored as chirality-based fluorescent turn-off/on probes for detection Hg2+ l-cysteine (l-Cys). Circular dichroism (CD) spectroscopy revealed that activity originates a synergy among intrinsic chirality, precursors on NCD surface, hybridization lower energy levels within embedded chromophore. Quantitative analysis optical asymmetry using Kuhn factor (g) at CD signal 312 nm showed higher value d-NCD230 (1.03 × 10–4) compared to l-NCD230 (1.13 10–5). Moreover, we demonstrated chirality transfer inversion phenomena d/l-NCDs by preparing with different precursor ratios temperatures probing them through spectroscopy. The NCDs exhibited selective fluorescence quenching presence Hg2+, demonstrating linearity Stern–Volmer plot. Limits (LODs) were calculated be 129 192 nM l-NCD230, respectively, 0–150 μM concentration range. mechanism involves nonradiative electron due binding oxygen-rich functional groups d/l-NCD230 surface. slight variation LOD values between indicates negligible effect sensing. Notably, intensity could restored upon adding l-cysteine, showing more pronounced enhancement than l-NCD230. This differential response is attributed preferential stereoselective interaction arising homochirality d-NCD230/Hg2+ l-cysteine. These findings demonstrate potential sensitive implications environmental monitoring biological sensing applications.
Language: Английский