Ultrathin selective molecularly imprinted polymer microdots obtained by evanescent wave photopolymerization

The fabrication of ultrathin selective molecularly imprinted polymer (MIP) microdots using polymerization by evanescent waves (PEW) is demonstrated for the first time. A specific prepolymerization mixture exhibiting suitable photosentivity at 405 nm was developed, containing in particular the visible-light photoinitiator bis(2,4,6-trimethylbenzoyl)-phenylphosphineoxide. PEW allows for nanometric resolution of the MIP dots in the z-scale. Within a few seconds, it is possible to generate molecularly imprinted microdots with sub-100 nm thickness. The amino acid Z-(l)-phenylalanine was used as model imprinting template, and the fluorescent dansyl-phenylalanine was employed as a fluorescently labeled derivative for the recognition tests. The MIP microdots showed specific molecular recognition for (l)-phenylalanine derivatives and were able to discriminate dansyl-(l)-phenylalanine from dansyl-(d)-phenylalanine.