Improving the sensitivity and selectivity of sulfonamides electrochemical detection with double-system imprinted polymers

The extensive use of antibiotics leading to the rapid spread of antibiotic resistance poses high health risks to humans, but to date there is still lack of an on-site detection method of SA residues. In this study, we integrated radical polymer-ization using sodium p-styrenesulfonate as a functional monomer and the self-polymerization of dopamine to prepare double-system imprinted polymers (DIPs) using sulfonamide antibiotics as templates. We found that the DIPs were semi-interpenetrating polymer networks and introduction of poly(dopamine) improved the selectivity of the imprinted cavities as well as the conductivity. The selectivity and sensitivity of the sensor using DIPs were much higher than those using single-system MIPs. This sensor could determine sulfonamides in complex samples in the presence of struc-tural analogues. The linear range was from 0.01 to 10.00 mu mol L-1 with a detection limit of 4.00 nmol L-1. Further-more, based on the highly selective DIPs and statistics analysis, this method could be used for simultaneous analysis of 4 sulfonamide types in real samples with an accuracy of 94.87%. This work provides a strategy to improve the selec-tivity and sensitivity of MIPs based-sensor that can serve as tool for the simultaneous analysis of antibiotic residues in environment samples.