Quantum carbon dots-doped hydrogel for simultaneous detection and adsorption of sulfisoxazole

Antibiotic residues have drawn global attention due to its potential risks of drug resistance, allergic reactions and cancer induction. Developing highly sensitive and efficient adsorbents for the detection and adsorption of antibiotics is significantly important. Hence, a novel quantum carbon dots-doped hydrogel (CQDs-DAH) using methacryloyloxyethyltrimethyl ammonium chloride (DMC), acrylamide (AM) and carbon quantum dots (CQDs) was prepared for simultaneous detection and adsorption of sulfisoxazole (SSX). The morphological structure and chemical composition of CQDs-DAH were thoroughly characterized. Remarkably, the hydrogel exhibited excellent selectivity and sensitivity toward SSX, achieving a low detection limit of 3.5 × 10 −4  mg/L and a linear detection range of 0–0.385 mg/L. Additionally, CQDs-DAH demonstrated exceptional adsorption performance in a solution with an initial SSX concentration of 50 mg/L, with a maximum capacity of 36.46 mg/g within just 20 min, following the Temkin isotherm and pseudo-second-order kinetic model. Thermodynamic analysis further revealed that the adsorption process was endothermic in nature. Furthermore, the mechanism underlying the adsorption and detection of SSX by CQDs-DAH was elucidated. CQDs-DAH offered a combination of rapid kinetics, high sensitivity, and dual functionality. This study provides valuable insights into the production of multifunctional adsorbents for the sensitive detection and efficient adsorption of SSX.