Fabrication of nanopatterned silicon structure via block copolymer lithography and its application to electrical biomolecule detection

Abstract

Block copolymer (BCP) lithography, a nanopatterning technology that exploits macromolecular self-assembly, is a promising candidate to overcome the inherent resolution limits of traditional photolithography. In this work, a nanopatterned electrical silicon biosensor is fabricated by BCP lithography and is used for the selective detection of similar structure model proteins. A cost-effective and large-area nanofabrication, based on BCP self-assembly and single-step dry etching, is developed for the hexagonal nanohole patterning of thin silicon films. The resultant nanopatterned electrical channel modified with biotin molecules successfully detects the two proteins, streptavidin and avidin down to nanoscale molarities (~1 nM). The nanoscale pattern comparable to Debye screening length and its large surface area of three-dimensional silicon nano-channel enable the biosensor to realize excellent sensitivity and stability. A device simulation is performed to demonstrate that the three-dimensional nanopatterned structure used in this study is effective for biomolecule detection. This nanofabrication based on scalable self-assembly approaches with a simple process offers a high throughput manufacturing route for clinical lab-on-a-chip diagnosis and relevant biomolecular studies.