Rose Bengal‐Derived Carbon Quantum Dots as a Fluorescence Probe for the Highly Sensitive Detection of Fe 3+ Ions

Abstract In this study, rose bengal‐derived carbon quantum dots (RB‐CQDs) was synthesized by a one‐step solvothermal method using rose bengal and 1,2‐phenylenediamine as precursors in ethanol at 180 °C for 10 h and purified by silica gel chromatography. The as‐synthesized RB‐CQDs disperses well in water with particle sizes ranging from 0.78 to 2.46 nm and exhibits excitation‐independent yellow fluorescent emission (529 nm), high quantum yield (44.3 %) and good biocompatibility. More importantly, the fluorescence of RB‐CQDs can be selectively quenched by Fe 3+ ions with good linear correlation and the detection limit is 19.9 nM. The recoveries of this method in actual water samples are 90 % to 110 % with relative standard deviations less than 5 %.