Fluorescence turn-off sensing of lead and gentamicin based on phosphorus and chlorine co-doped carbon dots

In the present study, CQDs co-doped with phosphorus and chlorine have been synthesized by a hydrothermal technique. The synthesized CQDs possess a mean size of < 20 nm and show excitation-independent features. The investigations presented that the CQD's fluorescence intensity was markedly quenched in the presence Pb2+ due to the formation of a stable non-luminescent complex that regarding this mechanism, a fluorescent platform was offered for Pb2+ ions in water samples. Furthermore, the gentamicin adding into the P, Cl-CQDs + Pb system had a more quenching effect on CQD's fluorescence and so another probe was proposed for gentamicin determina-tion. The detection limits for the proposed methods were 0.001 mu g.mL(-1) for Pb(2+)and 0.003 mu g.mL(-1) for gentamicin, respectively. The probe was successfully utilized in the environmental samples with high accuracy and selectivity.

Automated summary

In this study, CQDs co-doped with phosphorus and chlorine were successfully synthesized using a hydrothermal technique. The synthesized CQDs, with a mean size of < 20 nm, exhibited excitation-independent features. The fluorescence intensity of the CQDs was significantly quenched in the presence of Pb2+, forming a stable non-luminescent complex. This mechanism provided a fluorescent platform for the detection of Pb2+ ions in water samples. Additionally, the addition of gentamicin to the P, Cl-CQDs + Pb system further enhanced the quenching effect on the CQDs' fluorescence, leading to a new probe for gentamicin determination.