Lithographic patterning of antibodies by direct lift-off and improved surface adhesion

Abstract

The inherent property of antibodies binding to their antigen with high specificity makes them a strong candidate for sensing and detection applications. Microscale patterning of antibodies is desired for the miniaturization of sensors and fundamental cell biology studies. However, existing methodologies to pattern antibodies at the microscale are multi-step. In this work, we demonstrate microscale patterning of antibodies on a glass coverslip in a single step photolithography process. The microscale features of the photoresist were generated on the coverslip using photolithography, and the antibody solution was incubated. Acetone lift-off of the antibody incubated photoresist, and subsequent washing by isopropanol (IPA), produced a micro-array of antibodies. The functionality of patterned primary antibody was confirmed using the corresponding antigen and strict controls. One of the striking features of this method of patterning is that the process steps and chemicals inherently improve the adhesion between the antibodies and glass without the need to functionalize the glass surface. We performed an ultrasonication test, detergent washing test, and Scotch tape test to show improved adhesion. Using appropriate controls, we show that the interaction taking place between the antibodies and the glass surface, after our process, is stronger than the simple physisorption taking place between the antibodies and the glass surface, without any treatment.