Measurement using Fourier transform total reflectance optics

In early work (8) we used infrared spectroscopy coupled with attenuated total reflection optics. This work was done before the availability of infrared equipment based on Fourier transform methods. Due to their relative speed these methods now permit in situ, real time measurements with a resolution of 1 sec or less (9), and continue to yield valuable data, particularly in the hands of the Battelle group in a series of studies dating from 1979 (10). In our early infrared work we had to be content to rinse and dry the surface before obtaining the infrared reflection spectrum Nevertheless the values of surface concentration were remarkably close to those determined more recently. Infrared studies of proteins suffer generally from the fact that the main features of protein spectra are similar for all proteins and therefore it is difficult to distinguish one from another. 

Among these, some of the most frequently used are attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy. X-ray photoelectron spectroscopy (XPS), static secondary ion mass spectrometry (SSIMS), energy dispersive X-ray spectroscopy (EDS), optical microscopy, laser confocal scanning microscopy (LCSM), scanning electron microscopy (SEM), enviromnental scanning electron microscopy (ESEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), contact angle measurement, and some evaluation methods for the biocompatibility of membrane surfaces. 

NMR spectra were recorded using Bruker Biospin AV200 spectrometer (at 200 MHz for protons). Infrared spectra were recorded on a Bio-Rad FTS-40 attenuated total reflection Fourier transform IR (ATR-IR) using a horizontal ATR apparatus with a cadmium selenide crystal. Surface roughness was measured by an interferometerom-eter, which generates a 3D profile (Veeco WYKO NTllOO optical profiler). 

This study addresses the question of how bulk polymer chemistry and surface energy affect the amount and the conformation of FN adsorbed to a series of polyurethaneureas. The technique of Fourier transform infrared spectroscopy (FTIR) coupled with attenuated total reflectance (ATR) optics was used to continuously and non-invasively measure the kinetics of FN adsorption, as well as to monitor conformational changes occuring during adsorption. 

IR spectroscopic analysis was used to identify the surface modification of the wool fibres, using a Perkin - Elmo Fourier Transform infirared (FT-IR) spectrophotometer with Golden Gate attenuated total reflection (ATR) attachment. The Raman spectra were measured on die same spectrophotometer equipment with a FT-Raman module with Hd YAG lasa source. Spectra were accumulated fixrni 64 scans at a resolution of 4 cm. An optical bench alignment was performed before each Raman measurranent to ensure that the spectrometer was fine-tuned and the detector signal maximised. 

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