Azo-PMA nanopores of sub-20 nm length for unimolecular resolution of nucleic acids and proteins

Abstract

Owing to the facile fabrication and surface modification, the cost-effective polymer nanopores are widely employed in unimolecular determination of biomacromolecules and selective sensing of small molecules, nanoparticles and biomarkers. However, the documented polymer nanochannels are generally microscale in length with low spatial resolution. We herein synthesized azobenzene side-chain polymer (Azo-PMA) and spin-coated on silicon nitride membrane to obtain a polymer film of nanoscale thickness for further nanopore generation via controlled dielectric breakdown (CDB) approach. The Azo-PMA nanopores demonstrate good ions transporting activities, pH tolerance and stability in high concentration of electrolyte with low ionic current noise. In addition, the azobenzene-containing polymer nanopores exhibit photo-response upon UV/Vis. light irradiation. The Azo-PMA nanopore devices are utilized for linear and quadruple nucleic acids discrimination, sensing of proteins with distinct shapes and sizes, as well as the single amino acid resolution with good capture rate and sensitivity. We established an unimolecular sensing platform using polymer nanopores for nucleic acids and proteins detection with good spatial resolution, which will be an addition for the nanopore-carrier material exploration and applications in potential genomics and proteomics with high spatiotemporal resolution and low cost.

Keywords: Nucleic acids; Photo-response; Polyazobenzene membrane; Polymer/SiN(x) nanopore; Proteins.