Modular plasmonic nanopore for opto-thermal gating

TL;DR

This paper introduces a novel plasmonic nanopore system that enables rapid, optical, temperature-controlled gating of individual nanopores with high spatial resolution, advancing applications in biosensing and nanofluidics.

Contribution

It combines plasmonic resonators with thermoresponsive molecules to achieve fast, selective, and optical control of nanopore gating, a significant improvement over previous external heating methods.

Findings

Achieved 40 K/ms temperature change via thermo-plasmonics.

Demonstrated selective activation of individual nanopores in an array.

Enabled multiple ionic conductance states for logical gating.

Abstract

Solid-state nanopore gating inspired by biological ion channels is gaining increasing traction due to a large range of applications in biosensing and drug delivery. Integration of stimuli-responsive molecules such as poly(N-isopropylacrylamide) (PNIPAM) inside nanopores can enable temperature-dependent gating, which so far has only been demonstrated using external heaters. In this work, we combine plasmonic resonators inside the nanopore architecture with PNIPAM to enable optical gating of individual or multiple nanopores with micrometer resolution and a switching speed of few milliseconds by thermo-plasmonics. We achieve a temperature change of 40 kelvin per millisecond and demonstrate the efficacy of this method using nanopore ionic conductivity measurements that enables selective activation of individual nanopores in an array. Moreover, the selective gating of specific nanopores in an array can set distinct ionic conductance levels: low, medium, and high (i.e., 0, 1, and 2), which could be exploited for logical gating with optical signal control. Such selective optical gating in nanopore arrays marks a breakthrough in nanofluidics, as it paves the way towards smart devices that offer multifunctional applications including biosensing, targeted drug delivery, and fluidic mixing.