Glass nano/micron pipette-based ion current rectification sensing technology for single cell/vivo analysis

Abstract

Glass nano/micron pipette, due to its easy preparation, unique confined space at the tip, and modifiable inner surface of the tip, has the ability to capture the ion current signal caused by a single entity, making it widely used in the construction of highly sensitive and highly selective electrochemical sensor for single entities analysis. Compared with other solid-state nanopores, its conical nano-tip has less damage to cells when inserted into them, so it has become a powerful tool for in-situ analysis of important substances in cells. However, glass nanopipette has some shortcomings, such as poor mechanical properties, difficulty in precise preparation (aperture less than 50 nm), and easy blockage during complex real sample detection, which limit its practicability. Therefore, in recent years, researchers have conducted a series of studies on glass micropipette. Ionic current rectification technology is a novel electrochemical analysis technique. Compared with traditional electrochemical analysis methods, it does not generate redox products during the detection process, so it can not only be used for the determination of non-electrochemically active substances, but also has less damage to the cells/vivo analyzed in situ, becoming a powerful analysis technology for in-situ analysis of cells and vivo in recent years. In this review, we summarize the preparation and functionalization of glass nano/micron pipette, introduce the sensing mechanisms of two electrochemical sensing platforms constructed by glass nano/micron pipette-based ion current rectification sensing technology, as well as their applications in single cell/in vivo analysis, existing problems, and future prospects.