Chapter 5. A Confined Nanopipette: From Fundamental to Application

Nanopipettes are emerging as an effective technique for confined electrochemical sensing since they can be easily fabricated in a common wet chemical laboratory. The sensing performance of a nanopipette is greatly dependent on the small sharp tip, including its geometry, orifice size, taper length, pipette angle and even the surface properties. Compared with traditional protein and solid-state nanopores, nanopipettes own the nanopore located at the very tip of a centimetre length capillary. Its narrow shaft adjacent to the orifice provides a promising confined space in nanopipette-based electrochemical sensing. Accordingly, the fabrication of nanopipettes with the desired geometry and pore size is of fundamental importance in nanopipette-based sensing, as is detailed functionalization and characterization. In this chapter, we introduce the general preparation and modification of nanopipette, and further summarize the broad applications in electrochemistry, biochemistry, nanochemistry and other fields.