Accuracy of Graphical Slope Method versus Deconvolution for the Evaluation of Luminescent Lifetimes Using Various Pulsed Sources

Abstract

A quantitative evaluation has been made of the errors in luminescent lifetime calculations obtained by the graphical slope method when the data are distorted by the pulsed light source decay characteristics. The fluorophore lifetimes were calculated directly by the graphical slope method and were then deconvoluted to obtain the lifetimes undistorted by the pulsed source decay function. The percent error of the graphical slope method becomes significant (>5%) at luminescent-source lifetime differences of 2 nsec or less for pulsed sources having 1- to 3-nsec lifetimes. As the pulsed source lifetime increases, the percent errors will be greater at the same luminescent-source lifetime differences. As the luminescent lifetime approaches the pulsed source lifetime the percent error of the graphical method increases exponentially. The computer simulation procedure and a quantitative error analysis of the graphical slope and deconvolution methods are presented for a range of pulsed source decay values.