An integrated system for optical and electrical detection of single molecules/particles inside a solid-state nanopore

Abstract

Nanopore techniques have proven to be useful tools for single-molecule detection. The combination of optical detection and ionic current measurements enables a new possibility for the parallel readout of multiple nanopores without complex nanofluidics and embedded electrodes. In this study, we developed a new integrated system for the label-free optical and electrical detection of single molecules based on a metal-coated nanopore. The entire system, containing a dark-field microscopy system and an ultralow current detection system with high temporal resolution, was designed and fabricated. An Au-coated nanopore was used to generate the optical signal. Light scattering from a single Au-coated nanopore was measured under a dark-field microscope. A lab-built ultralow current detection system was designed for the correlated optical and electrical readout. This integrated system might provide more direct and detailed information on single analytes inside the nanopore compared with classical ionic current measurements.