title: Correction Approach for Delta Function Convolution Model Fitting of Fluorescence Decay Data in the Case of a Monoexponential Reference Fluorophore.
abstract: A correction is proposed to the Delta function convolution method (DFCM) for fitting a multiexponential decay model to time-resolved fluorescence decay data using a monoexponential reference fluorophore. A theoretical analysis of the discretised DFCM multiexponential decay function shows the presence an extra exponential decay term with the same lifetime as the reference fluorophore that we denote as the residual reference component. This extra decay component arises as a result of the discretised convolution of one of the two terms in the modified model function required by the DFCM. The effect of the residual reference component becomes more pronounced when the fluorescence lifetime of the reference is longer than all of the individual components of the specimen under inspection and when the temporal sampling interval is not negligible compared to the quantity (τR (-1) - τ(-1))(-1), where τR and τ are the fluorescence lifetimes of the reference and the specimen respectively. It is shown that the unwanted residual reference component results in systematic errors when fitting simulated data and that these errors are not present when the proposed correction is applied. The correction is also verified using real data obtained from experiment.
authors.affiliation: Photonics Group, Department of Physics, Imperial College London, Prince Consort Road, London, SW7 2AZ, UK. clifford.talbot@cncb.ox.ac.uk.
authors.forename: Clifford B
authors.initials: CB
authors.lastname: Talbot
authors.affiliation: Photonics Group, Department of Physics, Imperial College London, Prince Consort Road, London, SW7 2AZ, UK.
authors.forename: João
authors.initials: J
authors.lastname: Lagarto
authors.affiliation: Photonics Group, Department of Physics, Imperial College London, Prince Consort Road, London, SW7 2AZ, UK.
authors.forename: Sean
authors.initials: S
authors.lastname: Warren
authors.affiliation: Photonics Group, Department of Physics, Imperial College London, Prince Consort Road, London, SW7 2AZ, UK.
authors.forename: Mark A A
authors.initials: MA
authors.lastname: Neil
authors.affiliation: Photonics Group, Department of Physics, Imperial College London, Prince Consort Road, London, SW7 2AZ, UK.
authors.forename: Paul M W
authors.initials: PM
authors.lastname: French
authors.affiliation: Photonics Group, Department of Physics, Imperial College London, Prince Consort Road, London, SW7 2AZ, UK.|Centre for Histopathology, Imperial College London, Du Cane Road, London, W12 0NN, UK.
authors.forename: Chris
authors.initials: C
authors.lastname: Dunsby
mesh_terms: D005456:Fluorescent Dyes / Q000737:chemistry*; D016018:Least-Squares Analysis; D008962:Models, Theoretical; D017711:Nonlinear Dynamics; D012015:Reference Standards; D013050:Spectrometry, Fluorescence / Q000592:standards*
chemical_list: D005456:Fluorescent Dyes
keywords: Delta function convolution method (DFCM); Fluorescence decay curve fitting; Fluorescence lifetime; Reference reconvolution; Time-resolved spectroscopy