Ion Track-Based Nanofluidic Biosensors

Abstract

During the past decade, solid-state nanopores and nanochannels (SSNs) have emerged as a new class of devices for the creation of nanofluidic platforms with diverse applications. In particular, the precise control of ion transport achieved by SSNs paved the way to the development of specific and efficient biological and chemical iontronic sensors with promising technological potential. As biological ion channels play crucial roles in the regulation of vital processes for human cells, they have been a huge source of inspiration toward the design and construction of more sophisticated SSN devices. Today, the academic research on the topic has evolved to many concrete and practical usages, reflecting the potential commercial value of SSNs. Among the different methods available for the nanofabrication of single SSNs, high-energy ion beam (~MeV?GeV) techniques coupled to etching chemical processes are one of the most used due to their control on the size and geometry of the pore. The combination of this advanced nanofabrication technology and different surface functionalization strategies to confer specific target moiety responsiveness to the SSNs were the key point for the extraordinary advances in the area. This chapter aims to provide a closer look at the fabrication of SSNs by the ion-track-etching technology and the functionalization strategies in order to build SSNs for biosensing purposes.