In-tube micro-pyramidal silicon nanopore for inertial-kinetic sensing of single molecules

TL;DR

This paper introduces an in-tube micro-pyramidal silicon nanopore that uses inertial-kinetic forces for controlled, high-sensitivity biomolecular sensing, overcoming limitations of electrokinetic-driven translocation.

Contribution

It presents the first use of inertial-kinetic translocation in a micro-pyramidal silicon nanopore for biomolecular sensing, enabling regulated translocation and stable, high-sensitivity signals.

Findings

Achieved regulated protein translocation with adjustable dwell times

Demonstrated real-time molecular conformation discrimination

Enabled wireless monitoring of molecular reactions

Abstract

Electrokinetic force has been the major choice for driving the translocation of molecules through a nanopore. However, the use of this approach is limited by an uncontrollable translocation speed, resulting in non-uniform conductance signals with low conformational sensitivity, which hinders the accurate discrimination of the molecules. Here, we show the first use of inertial-kinetic translocation induced by spinning an in-tube micro-pyramidal silicon nanopore fabricated using photovoltaic electrochemical etch-stop technique for biomolecular sensing. By adjusting the kinetic properties of a funnel-shaped centrifugal force field while maintaining a counter-balanced state of electrophoretic and electroosmotic effect in the nanopore, we achieved regulated translocation of proteins and obtained stable signals of long and adjustable dwell times and high conformational sensitivity. Moreover, we demonstrated instantaneous sensing and discrimination of molecular conformations and longitudinal monitoring of molecular reactions and conformation changes by wirelessly measuring characteristic features in current blockade readouts using the in-tube nanopore device.