  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.
