Angew. Chem. Int. Ed. doi:10.1002/anie.200900950 (2009)

Credit: WILEY-VCH VERLAG GMBH & CO. KGAA

Etching precise protein patterns on a substrate is important both for medical diagnostics and for fundamental studies. Until now, this has usually been done by first creating protein-attracting regions and then filling in the rest of the surface with protein-repellent molecules.

Michael Zharnikov of the University of Heidelberg in Germany and his coworkers have now developed a technique that 'writes' protein patterns on to a substrate more easily. They do this by depositing an ethylene glycol layer on a gold surface and then zapping it with electron-beam lithography, creating hydrophobic areas that attract proteins only where the electron beam was focused (pictured; yellow dots represent adsorbed protein). If the adsorbed proteins carry specific binding sites, additional proteins can then be attached as a secondary patterning motif. The approach could lead to the creation of sophisticated 'biochips'.