Nanocavity protein biosensor - fabricated by molecular imprinting

A ´nanocavity´ protein biosensor fabricated using the molecular imprinting technique has been developed. We employed microcontact printing to form molecular imprints in a polymer thin-film to act as ´artificial antibodies´ for protein recognition. Proteins considered to be important biomarkers in clinical diagnosis were chosen as our templates, namely: Creactive protein, ribonuclease, lysozyme and myoglobin. In order to obtain the best thin-film composition with specific recognition sites, isothermal titration calorimetry was used as an auxiliary tool to examine enthalpy changes among the templates, the functional monomers and the cross-linkers. Nanocavities related to the shape of aggregated template proteins were observed on the imprinted surfaces by using atomic force microscopy (AFM). We found that by optimizing the composition ratio between the lowest affinity cross-linker and the highest affinity functional monomer highly selective recognition sites for a variety of template proteins were able to be formed.