Luminescence lifetimes are widely used as an analysis tool. Since decays in analytical systems are frequently complex decays rather than single exponentials, apparent lifetime methods based on the rapid lifetime determination (RLD) method or single frequency phase shift (SFPS) measurements are frequently used to reduce cost and simplify data analysis. It is demonstrated here that these methods can produce large errors under the right conditions. Both methods can give unexpected and uncharacteristic Stern-Volmer quenching plots (SVQPs) in two-component systems. Behaviors include bimodal quenching curves as well as "anti-quenching" curves. These phenomena are exacerbated by small fractions of long unquenched components.
Vol. 4, Iss. 6 Virtual Journal for Biomedical Optics
Sarah J. Payne, J. N. Demas, and B. A. DeGraff, "Abnormal Behavior in Stern–Volmer Luminescence Quenching Measurements via Apparent Lifetime Methods," Appl. Spectrosc. 63, 437-441 (2009)