Nitrogen-Doped Graphdiyne Quantum Dots for Electrochemical Chloramphenicol Quantification in Water

Nitrogen-doped graphdiyne quantum dots (NGDYQDs) have been synthesized hydrothermally from sp-hybridized N-doped graphdiyne and employed to fabricate an electrochemical sensor for the quantification of chloramphenicol (CAP), a typical nitro group-containing antibiotic, in water. The principle of this quantification is based on the high electrocatalytic activity of NGDYQDs to the reduction of −NO 2 groups in CAP to hydroxylamine groups. The effects of the electronic structure and size of the quantum dots on electrocatalytic activity were studied experimentally and theoretically. To prepare a sensor for CAP quantification, a suspension of NGDYQDs was prepared, and the NGDYQDs were deposited on a glassy carbon (GC) electrode. The prepared sensor showed a linear response to CAP from 0.1 to 114.5 μM with a limit of detection of approximately 5 nM (at a signal-to-noise ratio of 3) and a sensitivity of approximately 8.79 μA –1 μM –1 cm –2, as well as high repeatability, reproducibility, and stability. Moreover, the sensor has high selectivity and resistance to interference in the presence of other antibiotics (five randomly selected antibiotics: furazolidone, 2-nitroimidazole, amoxicillin, ciprofloxacin, and erythromycin), common biological compounds (glucose, ascorbic acid, and uric acid), common aqueous ions (Na +, K +, Fe 3+, Cu 2+, Ca 2+, Cl –, Br –, CO 3 2–, SO 4 2–, and NO 3 – ), other nitroaromatic compounds (4-nitrophenol and 4-nitroaniline), and common surfactants (sodium dodecyl sulfate and Triton X-100). Furthermore, the sensor was employed to quantify CAP in water samples with high accuracy. Thus, this work provides an electrochemical method for quantifying CAP in real samples with various applications such as biomedical analysis, environmental pollutant detection, and water safety evaluation.