Spectroscopic techniques luminescence lifetime measurements

Spectroscopic techniques based on the optical microscope are being used with increasing success in photophysics. Microscopic fluorescence decay measurements have been made on both thin liquid films and droplets of concentrated dye solutions.Illustrative data are given for rhodamine B in 20 pm films. A luminescence lifetime microscope spectrometer based on time-correlated single photon counting with an avalanche diode detector has measured... 

There is an impressive battery of spectroscopic techniques available for probing interactions between metal complexes and DNA. The oldest of these, UV/vis spectroscopy, is still one of the most sensitive ways to analyze dye-DNA interactions. For chiral metal complexes, circular dichroism is an invaluable tool. Fluorescence spectroscopy has in particular made great strides in recent years with respect to these applications, and aside from the measurement of simple emission from an excited metal complex, one can utilize emission polarization, luminescence lifetimes, and differential fluorescence quenching to obtain still more information about the environment about a metal complex. The application of ruthenium complexes, in particular, to developing probes for DNA, has been initiated in our laboratory and we focus here on some of its applications. 

Basically, instalments for measuring fluorescence and phosphorescence spectra have similar construction and should be called luminescence spectrometers. However the group of molecules that exhibit fluorescence is by far larger than that exhibiting phosphorescence, hence the term fluorescence spectrometer is used. The main spectral features of luminescence are spectral distribution, polarization and radiation lifetime. For analytical purposes spectral distribution and polarization are mainly used. Measuring the lifetimes requires a rather sophisticated time-resolved spectroscopic technique. It is very seldom used for analytical purposes and will not be discussed in this chapter. 

Unless otherwise noted, the aerogels were interrogated using standard spectroscopic instrumentation. The sensor respraises are recorded using a number of different types of spectroscopic measurements, including absorpti(Mi spectroscopy, luminescence emission and lifetime measurements, and Raman scattering techniques. 

This manuscript reports our characterization of these metal complex LB film materials. Simultaneously, we hope to develop a variety of spectroscopic techniques, most of which have b n employed previously with other LB film materids and in some cases for Ru (II) complexes. For example, luminescence spectra and lifetimes have been measured for a number of the Ru (II) complexes. The report (23) of the use of the luminescence photoselection method to determine order in LB films of pyrene-lecithin mixed materials is pertinent since we have experience (16-18) in the use of the photoselection method with Ru (D)... 

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