A method for fabricating protein patterns on the octadecyltrichlorosialne(OTS) surface through paper swabbing

A simple protein patterning procedure was developed for fabricating clean protein patterns ranging from nanometer to sub-millimeter scale. A carboxylic acid-terminated chemical pattern was fabricated first through the local probe oxidation on the octadecyltrichlorosilane (OTS) film under 100% relative humidity at the first. After incubating the chemical pattern in a protein solution, the sample was swabbed with a piece of ChemWipe paper to selectively remove the non-specifically adsorbed protein. After the swabbing, only the specifically immobilized protein remained on the surface, forming a protein pattern on the chemical template with a very clean background. In our approach, an anti-fouling surface or vigorous rinsing is not required, which simplifies the protein patterning process. As a demonstration of the capability of this protein patterning approach, we fabricated the lysozyme and catalase patterns on the OTS surface. Both patterns were clean and bioactive.