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

Time-of-flight Secondary Ion Mass Spectrometry (ToF-SIMS) and x-ray photoelectron spectroscopy (XPS) are used to characterize a newly synthesized glycosylated photoactivatable reagent designed for surface glycoengineering. The immobilization on diamond surfaces of the glycoaryldiazirine reagent lactose aryl diazirine (5-carboxamidopentyl-N-[m-[3-(trifluoromethyl)diazirin-3-yl]phenyl-β-D-galactopyranosyl]-(1->4)-1-thio-β-D-glucopyranoside) is compared to a previously studied monoglycosylated photoactivatable reagent (MAD-Gal). The XPS atomic constituents and chemical shifts, as well as ToF-SIMS specific characteristic fragments and molecular peaks of the new photoimmobilized molecule are recorded. Spectral differences are identified in XPS C 1s spectra and in the high mass range of positive 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 saccharides. Copyright © 2001 John Wiley & Sons, Ltd.