An excitation emission fluorescence lifetime spectrometer using a frequency doubled supercontinuum laser source

Melnikau, Dzmitry, Elcoroaristizabal, Saioa, & Ryder, Alan G. (2018). An excitation emission fluorescence lifetime spectrometer using a frequency doubled supercontinuum laser source. Methods and Applications in Fluorescence, 6 (045007). doi: 10.1088/2050-6120/aad9ae

Abstract

The accurate fluorescence analysis of complex, multi-fluorophore containing proteins requires the use of multi-dimensional measurement techniques. For the measurement of intrinsic fluorescence from tyrosine (Tyr) and tryptophan (Trp) one needs tuneable UV excitation and for steady-state measurements like Excitation Emission Matrix (EEM) simple pulsed Xe lamps are commonly used. Unfortunately, simultaneous multi-dimensional wavelength and time resolved measurement of intrinsic protein fluorescence in the 260 to 400 nm spectral range are challenging and typically required the use of very complex tuneable laser systems or multiple single excitation wavelength sources. Here we have assembled and validated a novel Excitation Emission Fluorescence Lifetime Spectrometer (EEFLS) using a pulsed, frequency doubled, Super-Continuum Laser (SCL) source coupled with a 16 channel multi-anode Time Correlated Single Photon Counting (TCSPC) measurement system. This EEFLS enabled the collection of near complete lifetime and intensity maps over the most important intrinsic protein fluorescence spectral range (lambda(ex) = 260-350/lambda(em) = 300-500 nm). The 4-dimensional (lambda(ex)/lambda(em)/I-(t)/tau) Excitation Emission Fluorescence Lifetime Matrix (EEFLM) data produced can be used to better characterize the complex intrinsic emission from proteins. The system was capable of measuring fluorescence emission data with high spectral (1-2 nm) resolution and had an Instrument Response Function (IRF) of similar to 650 ps for accurate measurement of nanosecond lifetimes. UV power output was stable after a warm up period, with variations of

Funder

Science Foundation Ireland

Publisher

IOP Publishing

Rights

Attribution-NonCommercial-NoDerivs 3.0 Ireland

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School of Biological and Chemical Sciences (Scholarly Articles)