Nanometer-sized molecular arrays on silicon surfaces

COLL 284

Chengzhi Cai, Jianhua Gu, Chi Ming Yam, Sha Li, and Guotin Qin. Department of Chemistry, University of Houston, 136 Fleming Building, Houston, TX 77204-5003
The ability to control the location of individual bio-molecules on bio-compatible surfaces will open new possibilities for biological research at nanoscale. Towards this goal, we have developed a new, robust system based on oligo(ethylene glycol) (OEG) monolayers grown by hydrosilylation (forming Si-C bonds) of OEG-terminated alkenes on hydrogen-terminated silicon surfaces. The results of ellipsometry, x-ray photoelectron spectroscopy, fluorescent imaging, and atomic force microscopy (AFM) studies showed that the OEG films prepared under optimized conditions strongly resisted the non-specific adsorption of a variety of proteins. We demonstrated that these atomically flat monolayers can be patterned by a biased AFM tip. The patterned areas bind a variety of proteins. In this way, we have prepared arrays of avidin spots. The diameters of the protein spots with an adjustable spacing are currently as small as 20 nm.