Cd. Tidwell et al., Static time-of-flight secondary ion mass spectrometry and x-ray photoelectron spectroscopy characterization of adsorbed albumin and fibronectin films, SURF INT AN, 31(8), 2001, pp. 724-733
Static time-of-flight secondary ion mass spectrometry (ToF-SIMS), monochrom
atized x-ray photoelectron spectroscopy (XPS) and I-125 radiolabeling have
been used to characterize albumin films adsorbed onto titanium, gold, polyt
etrafluoroethylene and r.f. glow discharge-deposited tetrafluoroethylene (T
FE) substrates. A comparison between albumin and fibronectin films also was
made. The intensities of characteristic amino acid mass fragments (immoniu
m ions) detected in the static ToF-SIMS experiments depended on the protein
type, the substrate type and the adsorption conditions, demonstrating the
sensitivity of static ToF-SIMS for probing the structure of adsorbed protei
n films. Based on the results from albumin and fibronectin, static ToF-SIMS
can provide information about the identity of adsorbed proteins and their
conformation, orientation, denaturation, etc. X-ray photoelectron spectrosc
opy can distinguish pure protein films, but the higher molecular specificit
y of static ToF-SIMS is more useful than XPS for examining complex protein
films. The I-125 radiolabeling experiments and the XPS atomic percentage of
nitrogen were used to quantify the amount of adsorbed protein. Copyright (
C) 2001 John Wiley & Sons, Ltd.