Development of nano-sozed bio-arrys using block copolymer self-assemblies

Abstract

In nanometric biomocular array, single molecule measurements require that the molecule in question is immobilized by binding to an appropriate surface. To avoid intermolecular interactions (and to achieve single molecule resolution in the case of optical measurement) a dilute array of binding sites, each designed to immobilize no more than one protein, would be ideal. To these ends, protein arrays with feature size smaller than 100nm have been fabricated, but it can not directly realize at single molecule level because those one spot or pattern size is yet much larger than one protein size. To achieve single molecule resolution, we have developed a novel fabrication method of nano-patterned array of bio-molecules with ultra-high density, using self-assembly of block-copolymers. The periodic spherical-domains of ordered block copolymers were obtained on the bio-compatible substrates. Compared to previous lithographic methods, self-assembly of block-copolymers makes it easier to fabrication of patterns with ~ 10 nanometer feature size and to reduce the number of processing steps. In this work, protein deposition on gold nanoparticles or protein conjugated gold nanoparticles onto PS nanostructure made by PS-PMMA block copolymer lithography formed stable 2D protein array. It is demonstrated that a nanoporous PS structure can serve as a spatial compartment maintaining patterned SAM and as a template material to form nano-array with a desirable orientation and separation of single protein molecule for detection of molecular interaction without interference intermolecular interaction.