This tutorial review will introduce and explore the fundamental aspects of nanopore (bio)sensing, fabrication, modification, and the emerging technologies and applications that both intrigue and inspire those working in and around the field. Although nanopores can be classified into two categories, solid-state and biological, they are essentially two sides of the same coin. For instance, both garner popularity due to their ability to confine analytes of interest to a nanoscale volume. Due to the vast diversity of nanopore platforms and applications, no single review can cover the entire landscape of published work in the field. Therefore, in this article focus will be placed on recent advancements and developments taking place in the field of solid-state nanopores. It should be stated that the intention of this tutorial review is not to cite all articles relating to solid-state nanopores, but rather to highlight recent, select developments that will hopefully benefit the new and seasoned scientist alike. Initially we begin with the fundamentals of solid-state nanopore sensing. Then the spotlight is shone on the sophisticated fabrication methods that have their origins in the semiconductor industry. One inherent advantage of solid-state nanopores is in the ease of functionalizing the surface with a range of molecules carrying functional groups. Therefore, an entire section is devoted to highlighting various chemical and bio-molecular modifications and explores how these permit the development of novel sensors with specific targets and functions. The review is completed with a discussion on novel detection strategies using nanopores. Although the most popular mode of nanopore sensing is based upon what has come to be known as ionic-current blockade sensing, there is a vast, growing literature based around exploring alternative detection techniques to further expand on the versatility of the sensors. Such techniques include optical, electronic, and force based methods. It is perhaps fair to say that these new frontiers have caused further excitement within the sensing community.

Nanopore biosensors have attracted attention due to their label-free single molecule detection capability. To date, different materials and applications have been shown in the field, varying from Si 3 N 4 to graphene and biomolecule sensing to DNA sequencing. Classical nanopore devices are composed of Si 3 N 4 material supported on a Si wafer and the detection is largely based on electrochemical sensing using chambers of ml volumes on both sides of the nanopore device. In this study, inflow label-free electrochemical detection of DNA molecules at single molecule level is shown using a classical Si 3 N 4 nanopore device integrated into a microfluidic device. The layout of the device given here set the basics for future works and discussions regarding future microfluidic integrated solid-state nanopores and the behaviour of the molecule under the influence of hydrodynamic flow.

Review: 68 refs.