Using a piezoelectric flow immunosensor for determining sulfamethoxazole in environmental samples

A mass-sensitive piezoelectric flow immunosensor for determining sulfo preparations in liquid media was proposed. This sensor included a piezoelectric quartz resonator with silver electrodes on the silanized surface of which sulfamethoxazole-protein conjugates were immobilized. The binding constants of antibodies with the conjugate sulfamethoxazole were determined, and the most active complementary pairs were chosen. The selectivity of determining sulfamethoxazole in the presence of its structural analogues was evaluated based on the cross reaction percentages. A procedure for the flow-injection determination of sulfamethoxazole was developed using the piezoelectric immunosensor as a detector; the detection limit of sulfamethoxazole was 0.15 ng/mL. The procedure was tested in determining sulfamethoxazole in soil and natural water.