Photochemistry is a powerful tool that can be used to selectively modify surface properties on soft (e.g. polystyrene) and hard (e.g. silicon wafer) substrates. Using light to impart functionality allows for the creation of a surface with high spatial resolution. In 2005, we photochemically patterned polymer substrates by functionalizing the surface with photoactive diblock copolymers. In the presence of a photoacid generator and subsequent exposure to UV light, tert-butyl acrylamide groups (Fig. 1a, solid red) were ‘deprotected’ to form acrylic acid groups (Fig. 1a, dotted red) in the irradiated regions. In 2006, we photopatterned phthalimide self-assembled monolayers (SAMs) by grafting polysaccharides onto silicon wafers (Fig. 2). In 2007, we photogenerated glycan arrays onto mixed phthalimide-amine SAMs: irradiation of the mixed SAMs in the presence of polysaccharides Polymer Photomodification of Soft and Hard Substrates Nicholas J. Turro and Jeffrey T. Koberstein, Columbia University G. T. Carroll, et. al. Langmuir 2006, 22, 2899; D. Wang, et al. Proteomics 2007, 7, 180. Soft Substrate Hard Substrate Figure 3. (a) Schematic of mixed SAM/polysaccharide irradiation. (b) Glycan array used to detect B. anthracis spore. Figure 1. (a) Schematic of ptBA/PAG irradiation. (b) Optical micrograph of a patterned PS substrate with ptBA and pAA regions indicating thickness changes perhaps due to loss of tert- butyl groups. F. Pan, P. Wang, K. Lee, A. Wu, N. J. Turro and J. T. Koberstein, Langmuir, 2005, 21, 3605. Photomask DUV PS substrate PAG PtBA PS 1) h 2) PAA PS substrate 100 m a) b) O CH 2 O O CH 2 O O H2C O O O H 2 C O O H 2 C O O H 2 C O O CH 2 O NH 2 Si O O NH 2 Si O O NH 2 Si O O NH 2 Si O O N Si OH O O O O NH 2 Si O O O CH 2 O O CH 2 O O H 2 C O O O NH 2 Si O O NH 2 Si O O NH 2 Si O O NH 2 Si O O N Si O O O O O NH 2 Si O O H 2 C O O H 2 C O O H 2 C O O CH 2 O h Antibodies a) b) Figure 2. Optical micrograph of water selectively condensed on regions of grafted polysaccharides (dark). CHE 0717518 CHE 0415516 DMR-0704054