Detection of metronidazole in honey and metronidazole tablets using carbon dots-based sensor via the inner filter effect.

Abstract

In this work, carbon dots (CDs) with a high quantum yield (22.3%) were easily prepared by hydrothermal pyrolysis of acid fuchsin 6B and hydrogen peroxide at 180°C for 10h. The resultant CDs possess a narrow size distribution in the range of 2.6 to 3.2nm and emit blue fluorescence. Interestingly, the absorption band of metronidazole (MTZ) centered at 318nm can complementary overlap with the excitation band of the as-prepared CDs centered at 320nm, resulting in an inner filter effect (IFE) in high efficiency. In fact, the fluorescence quenching of the CDs depends on the concentration of MTZ. Therefore, a simple method for the detection of MTZ can be established using the CDs-based sensor via the IFE. The linear range of the proposed method was 0-10μgmL-1 with the limit of detection as low as 0.257μgmL-1 . This CDs-based sensor had been applied for the detection of MTZ in honey and MTZ tablets with the recoveries in the range of 98.0% to 105.1% and 95.7% to 106.5%, respectively. Therefore, the as-prepared CDs have a potential to be developed as a MTZ sensor with high selectivity, sensitivity and accuracy.