On–Off–On Fluorescent Chemosensors Based on N/P-Codoped Carbon Dots for Detection of Microcystin-LR

The sensing of microcystin-LR (MC-LR) as a nonfluorescent species is still challenging since it has negligible influence on the emission fluorescent nanomaterials. Herein, well-defined “on–off–on” indirect chemosensing strategy developed by means nitrogen/phosphorus-codoped carbon dots (N/P CDs) for highly sensitive and selective MC-LR determination. nanoscale N/P CDs were conveniently synthesized one-step hydrothermal carbonization adenosine 5?-triphosphate (ATP) in aqueous media. fluorescence intensity was quenched presence Fe3+ due to formation Fe–O–P bonds between phosphate groups CDs. resulting CD-Fe3+ system MC-LR, its recovered dramatically quickly cavity competitively coordinated with Fe3+. Under optimized conditions, proposed chemosensor exhibited wide linear response range 0.05–3 ?g/L, detection limit down 17.1 ng/L. Moreover, successfully applied accurately detect real water samples achieved high recoveries 95.0–109.3%, relative standard deviations within 1.8–4.7%. By relying benefits chemosensors, such simple operation, low production cost, fast time, selectivity, sensitivity, platform possesses promising applicability determination complex environmental samples.