Simulating ATR spectra for detecting nerve agent-sorbent binding

Prototype simulations of attenuated total re ection (ATR) applied for infrared molecular binding spectroscopy, which is for nerve-agent detection, are presented. The simulations use: calculated estimates of permitivity functions (for the custom sorbent SiFA4H, nerve agent simulant DMMP and molecular structure SiFA4H-DMMP); and a model of re ection from multicomponent-multilayer systems, which is based on the scattering-matrix representation of electromagnetic-wave propagation. The physical assumptions and approximations underlying these simulations, and model-parameter sensitivity are examined with respect to quantitative prediction of ATR spectra associated with nerve-agent detection. Experimentally measured ATR spectra are utilized for qualitative comparison and quantitative adjustment of model parameters.