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

Quenching-based luminescence sensors generally are supported in organic or inorganic polymers and exhibit nonlinear Stern-Volmer quenching behavior. Two common explanations of the nonlinearity are either multisite binding or the nonlinear solubility properties of the analyte in the 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 different 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 computational slightly simpler to use, but the two-site model seems to better approximate the underlying chemistry of systems studied to date.