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.