MODELING OF LUMINESCENCE QUENCHING-BASED SENSORS - COMPARISON OF MULTISITE AND NONLINEAR GAS SOLUBILITY MODELS

Quenching-based luminescence sensors generally are supported in organi c or inorganic polymers and exhibit nonlinear Stern-Volmer quenching b ehavior. Two common explanations of the nonlinearity are either multis ite binding or the nonlinear solubility properties of the analyte in t he sensor. Both models have three fitting parameters. These two models are compared, and the merits of each are discussed. It is shown that while the underlying physical bases of tbe two models are radically di fferent and chemically incompatible, the two models are mathematically equivalent for data fitting. The correspondence of parameters in the two models is given. The nonlinear solubility model is probably comput ational slightly simpler to use, but the two-site model seems to bette r approximate the underlying chemistry of systems studied to date.