Green synthetic nitrogen-doped graphene quantum dot fluorescent probe for the highly sensitive and selective detection of tetracycline in food samples

Tetracycline (TC) is a broad-spectrum antibiotic. When humans consume too much food containing tetracycline residues, it can be a serious health hazard. Therefore, it is essential to develop a strategy to detect TC. In this study, we prepared light blue-green luminescent nitrogen-doped graphene quantum dots (N-GQDs) by a hydrothermal method using the natural products potato straight-chain starch and urea as precursors; the fluorescence quantum yield of the prepared N-GQDs was 5.2%. We investigated the detection of tetracycline (TC) by this N-GQD fluorescent sensor based on the internal filtration effect (IFE) of TC on N-GQDs. The reaction is green, simple and no other contaminating products are present. A good linear relationship was established between the relative fluorescence intensity ratio of the system and the logarithm of the TC concentration of 2.5 x 10(-10) to 5 x 10(-6) M (R-2 = 0.9930), with a detection limit of 9.735 x 10(-13) M. The method has been used to analyze TC in three real food samples (whole milk, skim milk, honey) with low detection limits (3.750 x 10(-11) to 2.075 x 10(-9) M), wide linear range, and satisfactory recoveries of 93.80-109.20% were obtained. In conclusion, the proposed method is a green, rapid, highly sensitive and selective method for the detection of tetracycline in real food samples, demonstrating the potential application of N-GQDs in food detection.

Automated summary

In this study, nitrogen-doped graphene quantum dots (N-GQDs) were prepared and used for the detection of tetracycline (TC) based on the internal filtration effect. The method showed greenness, rapidity, high sensitivity, and selectivity, making it suitable for real food samples.