Concentration-regulated multi-color fluorescent carbon dots for the detection of rifampicin, morin and Al3+

Carbon dots have many new and interesting phenomena, and the concentration dependent luminescence wavelength is an intriguing one. Herein, nitrogen-sulfur co-doped carbon dots (NSCDs) diluted to different concentrations, the high concentration of G-NSCDs (0.2 mg mL-1) with green fluorescence and the low-concentration of B-NSCDs (0.01 mg mL-1) with blue fluorescence were obtained. Further, it was found that the detection behaviors are different for different concentrations. The turn-off fluorescent sensor of G-NSCDs can specifically recognize rifampicin in a linear range of 0.2-20 mM with a detection limit of 56.6 nM employing the mutual effect of photo-induced electron transfer and dynamic quenching. Meanwhile, a turn-off B-NSCDs fluorescence sensor was constructed to effectively identify morin based on the internal filtration effect and static quenching, achieving a suitable linearity of 0.2-30 mM and a detection limit of 51.2 nM. Due to the strong chelation of morin and Al3+, a turn-on fluorescent probe for sequential detection Al3+ was fabricated based on B-NSCDs-morin system, obtaining a good linearity of 0.1-2.0 mM with a satisfactory detection limit of 45.8 nM. These interesting behaviors indicate that NSCDs are expected to become novel sensing materials for the monitoring of rifampicin, morin and Al3+ in organisms, which is beneficial for our health.& COPY; 2023 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

Nitrogen-sulfur co-doped carbon dots (NSCDs) exhibit concentration-dependent luminescence wavelength, with G-NSCDs displaying green fluorescence at high concentrations and B-NSCDs showing blue fluorescence at low concentrations. The detection behaviors of NSCDs vary with different concentrations, providing a means for sensing rifampicin, morin, and Al3+ in organisms.