Integrated direct DNA/protein patterning and microfabrication by focused ion beam milling

Abstract

A novel method for patterning biomolecules, termed FIB biolithography was invesigated. The starting material was a silicon wafer coated with 1000Å film of SiO2. Thiol-modified oligonucleotides or proteins were covalently immobilized onto substrate surface by disulfide bond formation and Sciff's base formation. A dextran stabilization layer was applied to improve biofunctionality retention. A gold film layer was deposited onto the immobilized biomolecule layer by vacuum evaporation. The gold film served as a protective layer for the underlying biomolecules. FIB milling was performed for patterning of the surface. It was observed that the method can be applied for biomolecule patterning and microfabrication in prefabricated structures or devices where precise local manipulation is needed.