Advances in nanofluidic field-effect transistors: external voltage-controlled solid-state nanochannels for stimulus-responsive ion transport and beyond.

Ion channels, intricate protein structures facilitating precise ion passage across cell membranes, are pivotal for vital cellular functions. Inspired by the remarkable capabilities of biological ion channels, the scientific community has ventured into replicating these principles in fully abiotic solid-state nanochannels (SSNs). Since the gating mechanisms of SSNs rely on variations in the physicochemical properties of the channel surface, the modification of their internal architecture and chemistry constitutes a powerful strategy to control the transport properties and, consequently, render specific functionalities. In this framework, both the design of the nanofluidic platform and the subsequent selection and attachment of different building blocks gain special attention. Similar to biological ion channels, functional SSNs offer the potential to finely modulate ion transport in response to various stimuli, leading to innovations in a variety of fields. This comprehensive review delves into the intricate world of ion transport across stimuli-responsive SSNs, focusing on the development of external voltage-controlled nanofluidic devices. This kind of field-effect nanofluidic technology has attracted special interest due to the possibility of real-time reconfiguration of the ion transport with a non-invasive strategy. These properties have found interesting applications in drug delivery, biosensing, and nanoelectronics. This document will address the fundamental principles of ion transport through SSNs and the construction, modification, and applications of external voltage-controlled SSNs. It will also address future challenges and prospects, offering a comprehensive perspective on this evolving field.