A parylene lift-off process with microfluidic channels for selective protein patterning

This paper describes a method for high resolution and selective patterning of proteins using a patterned parylene film and PDMS microchannels. Solutions containing desired materials are delivered through the microchannels to the patterning spots where the parylene film is perforated in a desired pattern. Proteins are patterned on a planar substrate after being immobilized on the spots, and subsequently both the PDMS and parylene layers are peeled off. Using this method, fine patterns of bovine serum albumin (BSA) in arrays of 20 mu m x 20 mu m spots at 2 mu m intervals were achieved. Selective patterning of multiple fluorescent beads was also demonstrated. This method can be performed under the wet condition, which prevents the drying out of proteins and is useful for selective protein patterning with minimal nonspecific binding on the undesired area.