Ag-Decorated Ti ₃ C ₂ Magnetic Nanosheets for Determination of Quinolone Antibiotics in Environmental Waters

Quinolone antibiotics (QNs), a pivotal kind of antibiotics, may pose potential risks to human health through trophic transfer and bioaccumulation via the food chain. In this work, magnetic NiFe 2 O 4 @Ti 3 C 2 @Ag nanocomposites (NiFe 2 O 4 @Ti 3 C 2 @Ag NCs) were fabricated by anchoring NiFe 2 O 4 nanoparticles on Ti 3 C 2 nanosheets followed by surface thiol modification and in situ growth of Ag nanoclusters. The two-dimensional Ti 3 C 2 nanosheets provided a robust support for magnetic nanoparticle immobilization, and surface-grown Ag nanoclusters created nanoscale interfacial affinity adsorption sites for quinolone antibiotics. NiFe 2 O 4 @Ti 3 C 2 @Ag NCs demonstrated favorable chemical stability and expected adsorption capacity for QNs, and the adsorption conformed to the pseudo-first-order kinetic and Redlich–Peterson isotherm models, indicating that the adsorption of QNs was nonuniform and multilayered interactions. Based on NiFe 2 O 4 @Ti 3 C 2 @Ag NCs, a magnetic solid-phase extraction (MSPE) combined with high-performance liquid chromatography (HPLC-UV) was developed for the rapid detection of QNs in environmental water samples. Under the optimal operational conditions, the experimental results indicated that the present method achieved a noticeable linearity over the concentration range of 0.5–300 μg L –1 and limits of detection (LODs) in the range of 0.031–0.171 μg L –1 . The extraction efficiencies of six QNs ranged from 92.1 to 95.9%, and the enrichment factors ranged from 92.0 to 95.9. The intraday and interday precisions were over the range of 1.1–2.1 and 1.5–2.7%, respectively. The established method was evaluated with different real water samples, and the spiked recoveries ranged from 85.9 to 96.5%. The abovementioned results demonstrated that the established method was reliable and effective for monitoring trace QNs in the environment.