Improving Protein Transfer Efficiency and Selectivity in Affinity Contact Printing by Using UV-Modified Surfaces

Affinity contact printing (αCP) is a technique that allows the selective capture of a target protein from solutions to a polymeric stamp decorated with an antibody, and then the target protein is printed onto a solid surface. The success of αCP critically relies on the precise control of protein-surface interactions. Here, we report a study on the effect of UV on the protein-surface interactions between protein and polydimethylsiloxane stamps and between protein and glass slides decorated with N,N-dimethyl-n-octadecyl-3-aminopropyltrimethoxysilyl chloride (DMOAP). Our results show that UV-modified surfaces can be used to improve the transfer efficiency and selectivity of proteins during αCP. For example, the protein transfer efficiency of human IgG onto a DMOAP-coated slide increases from 7.2% to 45.1% after the UV treatment. On the basis of these results, UV-modified surfaces were employed to develop a αCP system for protein detection. The detection limit of anti-IgG in this system is around 10 ng/mL, and the dynamic range is 4 orders of magnitude.