In situ monitoring of the selective adsorption mechanism of small environmental pollutant molecules on aptasensor interface by attenuated total reflection surface enhanced infrared absorption spectroscopy (ATR-SEIRAS)

Abstract In situ monitoring of the interactions and properties of pollutant molecules at the aptasensor interface is being a very hot and interesting topic in environmental analysis since its charming molecule level understanding of the mechanism of environmental biosensors. Attenuated total reflection surface enhanced infrared absorption spectroscopy (ATR-SEIRAS) provides a unique and convenient technique for the in situ analysis, but is not easy for small molecules. Herein, an ATR-SEIRAS platform has been successfully developed to in situ monitor the selective adsorption mechanism of small pollutant molecule atrazine (ATZ) on the aptasensor interface by characteristic N-H peak of ATZ for the first time. Based on the constructed ATR-SEIRAS platform, a thermodynamics model is established for the selective adsorption of ATZ on the aptasensor interface, described with Langmuir adsorption with a dissociation constant of 1.1 nM. The adsorption kinetics parameters are further obtained with a binding rate constant of 8.08×105 M−1·s−1. A promising and feasible platform has therefore successfully provided for the study of the selective sensing mechanism of small pollutant molecules on biosensors interfaces, further broadening the application of ATR-SEIRAS technology in the field of small pollutant molecules.