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

Graphical A method for the synthesis of Nitrogen-Doped Carbon quantum Dots (N-CQDs) with 4-aminosalicylic acid and tartaric acid is proposed. The synthesized N-CQDs exhibit strong fluorescence and good photostability and can selectively detect CN − in solution. 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).