Membrane Chromatographic Test System for Determining Bisphenol A in Drinking Water Based on the Use of an Aptamer

For the rapid determination of bisphenol A in drinking water, a membrane test system has been developed using a conjugate of gold nanoparticles with an aptamer that specifically binds the target analyte, and a conjugate of mercaptosuccinic acid with a carrier protein impregnated in the test zone of the strip. The working principle of the test system is based on the binding of free gold nanoparticles in the test zone, formed as a result of the competitive interaction of the aptamer with bisphenol A and its release from the surface of gold nanoparticles. Conjugates of gold nanoparticles with aptamers of different compositions were obtained and tested. Optimal conditions were selected to ensure the achievement of a low detection limit for bisphenol A. The developed test system allows the detection of bisphenol A within 15 min with a detection limit of 13.5 ng/mL. The suitability of the test system was confirmed when testing drinking water; the recovery values of bisphenol A ranged from 88.2 to 101.3%.