Optimization of As(Ш) imprinted polymers and dynamic recognition mechanism revelation from perspective of target-monomer interaction

Abstract

Molecular imprinted polymers (MIPs) have been recognized as good adsorbents to detect and remove As(Ш) from environment. 2-mercaptonicoic acid (2-M), having high affinity towards H3AsO3, is considered as potential functional monomer of H3AsO3 MIPs. In this work, a template-monomer binding affinity guide strategy was applied to investigate self-assembling conditions of H3AsO3 MIPs with 2-M as functional monomer, using quantum chemistry calculation and molecular dynamics simulation. Afterwards, dynamic recognition mechanism of H3AsO3 MIPs was unraveled through imprinted cavity modelling for the first time. Results show that dichloromethane is the most suitable solvent, and 1:4:250 of H3AsO3, 2-M and dichloromethane is the best ratio. Remarkably, the direct observation of dynamic evolution of targets recognition was achieved by constructed annular imprinted cavity models with optimal 20 TEOS as cross-linkers. It was found that the critical distance for H3AsO3 recognition is 3.0 Å. The dominant binding interaction is clarified to be hydrogen bond, and the initial driving force was S-H···O bond formation. This work provides not only a feasible strategy for computational design of good-performance MIPs, but also a method to perform recognition mechanism study by imprinted cavity modelling, which is significant for MIPs development as adsorbents for contaminants detection and removal from environment.