Synchronized Optical and Electronic Detection of Biomolecules Using a Low Noise Nanopore Platform

Abstract

In the past two decades there has been a tremendous amount of research into the use of nanopores as single molecule sensors, which has been inspired by the Coulter counter and molecular transport across biological pores. Recently, the desire to increase structural resolution and analytical throughput has led to the integration of additional detection methods such as fluorescence spectroscopy. For structural information to be probed electronically high bandwidth measurements are crucial due to the high translocation velocity of molecules. The most commonly used solid-state nanopore sensors consist of a silicon nitride membrane and bulk silicon substrate. Unfortunately, the photoinduced noise associated with illumination of these platforms limits their applicability to high-bandwidth, high-laser-power synchronized optical and electronic measurements. Here we present a unique low-noise nanopore platform, composed of a predominately Pyrex substrate and silicon nitride membrane, for synchronized optical and electronic detection of biomolecules. Proof of principle experiments are conducted showing that the Pyrex substrates have substantially lowers ionic current noise arising from both laser illumination and platform capacitance. Furthermore, using confocal microscopy and a partially metallic pore we demonstrate high signal-to-noise synchronized optical and electronic detection of dsDNA.

Selective single molecule nanopore sensing of proteins using DNA aptamer-functionalised gold nanoparticles

“…To circumvent this problem, single molecule methods have been developed based on either optical or electrical readout. 3,4 …”

Wafer-scale fabrication of fused silica chips for low-noise recording of resistive pulses through nanopores

“…Besides the dielectric properties, photo-induced noise by laser illumination of silicon chips limits their application in combined electronic and optical measurements [37]. Li et al suggested that laser-induced ionic current noise results from a photo-induced electrochemical catalytic process at the interface of the semiconductor and the electrolyte [40].…”

“…Chips with nanopores for resistive pulse sensing usually consist of a support material with a cavity on one side, which leads to a freestanding membrane containing a nanopore. These freestanding membranes are commonly prepared by thin-film deposition techniques such as low-pressure chemical vapor deposition (LPCVD) or plasma enhanced chemical vapor deposition (PECVD), while the cavities are typically defined using photolithography and formed using dry and wet etching [26,[31][32][33][34][35] or by a membrane transfer technique [36][37][38][39]. Most chips used for nanopore recordings are silicon based [26,31,33,35,36].…”

Through a Window, Brightly: A Review of Selected Nanofabricated Thin-Film Platforms for Spectroscopy, Imaging, and Detection

“…Fluorescence is the most likely optical technique to be used in conjunction with a nanopore, but one could imagine that a suitably structured gold film, separated by a well-defined nanopore gap containing an analyte, might also be used for surface-enhanced Raman spectroscopy. 20,27,46,61,90,[267][268][269][305][306][307][308][309][310][311][312][313][314][315] Extensions to Nanopore Arrays. We conclude our discussion of the merging of physical-and optical-based nanopore sensing and manipulation approaches, with the consideration of nanopore arrays.…”