Synthesis of nitrogen and sulfur codoped carbon dots and application for fluorescence detection of Cd(ii) in real water samples

摘要

Herein, nitrogen and sulfur codoped carbon dots (N&S CDs) were prepared by a facile hydrothermal process and they could be introduced as a fluorescent probe for the determination of cadmium ions (Cd2+), yielding high sensitivity and excellent selectivity. The obtained N&S CDs exhibited bright blue fluorescence with a quantum yield of 40% and exhibited a fast responsive fluorescence quenching signal within 2 min toward Cd2+ in both ultrapure water and real water samples. The CDs responded to Cd2+, which acted as a quencher of blue fluorescence at 459 nm with the limit of detection of 0.018 mu M in the range of 0.02-1 mu M. The quenching fluorescence behavior was found to obey the static quenching effect (SQE). The low toxicity and good cell permeability of CDs were verified by cell experiments.