A novel molecularly imprinted electrochemical sensor based on quasi-three-dimensional nanomaterials Nb₂CTx/AgNWs for specific detection of sulfadiazine

A novel molecularly imprinted electrochemical sensor (MIECS) was constructed for the specific detection of sulfadiazine (SDZ) in food. Niobium carbide (Nb₂CTx) as a typical two-dimensional lamellar nanomaterial has good electrical conductivity and unique structure, which was assembled with one-dimensional silver nanowires (AgNWs) to form quasi-three-dimensional composite nanomaterials (Nb₂CTx/AgNWs). As spacer material, AgNWs prevented the aggregation of Nb₂CTx and the collapse of Nb₂CTx layers. At the same time, a fast electron transport channel was constructed through the synergistic effect between nanomaterials the two. The Nb₂CTx/AgNWs realized the enhancement of electrical signals. Molecularly imprinted polymers (MIPs) endowed the sensor with selectivity, achieving the specific detection of sulfadiazine. Under the optimal experimental conditions, the method has a wide linear range (1 × 10⁻⁸–1 × 10⁻⁴ mol L⁻¹) and a low limit of detection (1.30 × 10⁻⁹ mol L⁻¹). The sensor was used to detect sulfadiazine in pork, chicken, and feed samples, and the recovery was 82.61–94.87%. The results were in good agreement with the HPLC results, which proved the accuracy and practicability of the method.