Total internal reflection intrinsic fluorescence

Proteins containing amino acids like tryptophan and tyrosine which intrinsically fluoresce upon excitation in the ultraviolet range can be employed, hence, the name total internal reflection intrinsic fluorescence-TIRIF, or... 

VanWagenen, R. A., Rockhold, S., Andrade, J. D., Probing Protein Adsorption Total Internal Reflection Intrinsic Fluorescence , in Interfacia Phenomena and Applications, Cooper, S. L., Pappas, N. A. (eds.) New York Wiley, 1982, p. 351. 

Total internal reflection intrinsic fluorescence (TIRIF) spectroscopy and molecular graphics have been applied to study the adsorption behavior of two lysozymes on a set of three model surfaces. A recently devised TIRIF quantitation scheme was used to determine adsorption isotherms of both hen egg-white lysozyme (HEWL) and human milk lysozyme on the three model surfaces. This preliminary study suggests that the adsorption properties of the two lysozymes are significantly different, and that further comparative studies of the two lysozymes might prove to be beneficial in understanding how protein structure might influence adsorption properties. Molecular graphics was used to rationalize the adsorption results from TIRIF in terms of the proteins surface hydrophobic/hydrophillic character. 

Among the other spectroscopies, either in the direct or reflection mode, fluorescence spectroscopy may be mentioned. A promising variant is Total Internal Reflection Fluorescence spectroscopy (TIRF). The decay rate of an excited fluorescing probe is usually Interpreted in terms of the local fluidity and polarity. The technique has been used to estimate the extent of ordering inside adsorbed surfactant layers, but this is not an absolute method because a fluorescent probe has to be inserted, and such probes themselves affect the local fluidity. More rigorous are fluorescence experiments with molecules that possess such a probe as an intrinsic part of their structure, such as tryptophans in... 

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