ToF-SIMS and XPS study of photoactivatable reagents designed for surface glycoengineering part III. 5-carboxamidopentyl-N-[m-[3-(trifluoromethyl)diazirin-3-yl]phenyl-beta-D-galactopyranosyl]-(1-> 4)-1-thio-beta-D-glucopyranoside (lactose aryl diazirine) on diamond

Time-of-night Secondary Ion Mass Spectrometry (ToF-SIMS) and x-ray photoele ctron spectroscopy (XPS) are used to characterize a newly synthesized glyco sylated photoactivatable reagent designed for surface glycoengineering. The immobilization on diamond surfaces of the glycoaryldiazirine reagent lacto se aryl diazirine (5-carboxamidopentyl-N-[m-[3-(trifluoromethyl)diazirin-3- yl]phenyl-beta -D-galactopyransol]-(1->4)-thio-beta -D-glucopyranoside)-bet a -D-glucopyranoside) is compared to a previously studied monoglycosylated photoactivatable reagent (MAD-Gal). The XPS atomic constituents and chemica l shifts, as well as ToF-SIMS specific characteristic fragments and molecul ar peaks of the new photoimmobilized molecule are recorded. Spectral differ ences are identified in XPS C 1s spectra and in the high mass range of posi tive ion ToF-SIMS spectra for the surface immobilized disaccharide. The ToF -SIMS characteristic high-mass ions involve both cationization with Na+ and loss of the diazirine function. The results can be related to differences observed in biological assays with each of the surface immobilized sacchari des. Copyright (C) 2001 John Wiley & Sons, Ltd.