Functionalized silicone nanofilaments: a novel material for selective protein enrichment.

We present a simple and versatile technique of tailoring functionalized surface structures for protein enrichment and purification applications based on a superhydrophobic silicone nanofilament coating. Using amino and carboxyl group containing silanes, silicone nanofilament templates were chemically modified to mimic anionic and cationic exchange resins. Investigations on the selectivity of the functionalized surfaces toward adsorption of charged model proteins were carried out by means of fluorescence techniques. Due to a high contact area resulting from the nanoroughness of the coating, excellent protein retention characteristics under various conditions were found. The surfaces were shown to be highly stable and reusable over several retention-elution cycles. Especially the full optical transparency and the possibility to use glass substrates as support material open new opportunities for the development of optical biosensors, open geometry microfluidics, or lab-on-a-chip devices.