Fluorescent detection of antibiotics in dairy products and household water using biocompatible doped carbon dots

The identification of antibiotic residues in food and water is essential for public health and environmental protection. This study involved the synthesis of carbon dots (ADCDs) utilizing l-arginine and diethylenetriamine as nitrogen-rich precursors to amplify fluorescence characteristics. The structural and chemical content of ADCDs was validated using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS), confirming effective doping and surface functionalization. The synthesized HCDs demonstrated robust fluorescence, superior water dispersibility, and remarkable photostability, facilitating the selective detection of ampicillin in milk and tap water. The study of the actual sample exhibited elevated recovery rates (82.00 %–98.77 %) alongside a low relative standard deviation (RSD), so validating the sensor's precision and consistency. MTT assays and fibroblast proliferation analysis demonstrated over 80 % cell viability, confirming the biosafety of the nanomaterial. The integration of green synthesis, intrinsic doping and fluorescence-based sensing offers a cost-effective and efficient method for antibiotic monitoring.