Synthesis of Nitrogen‐Doped Carbon Quantum Dot (N‐CQDs) for Cyanide Detection

Abstract Selective and sensitive detection of Cyanide (CN − ) is critical essential due to it is one of the most lethal chemicals and threat to human health. In this study, nitrogen‐doped carbon quantum dots (N‐CQDs) were synthesized by one‐step hydrothermal method using 4‐aminosalicylic acid and tartaric acid as raw materials. The prepared N‐CQDs were spherical particles with good water solubility and uniform particle size distribution, the optimal excitation and emission wavelengths of N‐CQDs were 495 nm and 514 nm, respectively. Based on the selective fluorescence quenching effect between CN − and N‐CQDs, achieving accurate and rapid detection of CN − . Fluorescence quantum yield (PLQY) of N‐CQDs is 39 %, and the other competing anions showed little or no interference to CN − . For highly sensitivity detections of N‐CQDs under optimal conditions, the fluorescence quenching degree was linearly correlated with the CN − concentration in the range of 0–100 μM (R 2 =0.9929).