Atomic force microscopic analysis of highly defined protein patterns formed by microfluidic networks

This paper describes the formation of highly defined two-dimensional protei n arrays onto a polymeric substrate expressing biotin functionalities at it s surface. Micron-scale arrays of avidin were created by exploiting its int eraction with biotin, thereby creating a versatile patterned surface onto w hich any biotinylated species can be subsequently immobilized. The patterni ng process utilized the technique of microfluidic networks (mu FN) to spati ally confine the flow of protein solution on a substrate. We describe metho ds developed to control protein deposition with nanometer-scale precision. Utilizing atomic force microscopy (AFM), these patterned surfaces were anal yzed to the molecular level. In addition, the applicability of this techniq ue to a wider range of substrates has been investigated. In particular, dev elopments within the mu FN technique have enabled the successful formation of protein micropatterns onto a highly hydrophilic surface, a substrate whi ch is generally not suited to the technique of mu FN.