Detection of Au Nanoparticles Using Peptide-Modified Si₃N₄ Nanopores

Solid-state nanopores can be used as affordable and user-friendly detectors for biological molecules such as DNA, RNA, and proteins. Here, we used chemically modified silicon nitride nanopores to detect nanoparticles. The nanopores were modified with a peptide-based coating that significantly improved the pore current stability when compared to uncoated pores. The translocation of charged gold nanoparticles through the nanopore was characterized both for single particles (monomers) and for structures of two particles (dimers), connected by individual double-stranded DNA molecules. The monomers and dimers differ in their translocation time through the nanopore. The developed nanopore/nanoparticle-based system is a promising platform for the detection of DNA and other molecules for diagnostic purposes.