Fabrication and Single Cell Imaging Applications of Glass Nanopipettes in Undergraduate Analytical Chemistry Laboratory

Electrochemical analysis is one of the important parts in undergraduate analytical chemistry. Here, we present a comprehensive experiment project for upper-division undergraduate students in chemistry. In this experiment, glass nanopipettes with a tip size of about 100 nm were fabricated and applied for single cell fluorescence imaging. The nanopipette was filled with fluorescent molecules and inserted into a selected single cell. Upon applying a constant DC voltage, the fluorescent molecules could be precisely delivered to the designated subcellular location due to the electro-osmotic flow generated inside the nanopipette. The basic principles of nanopipette-based single cell perfusion and fluorescence labeling in the cytoplasm were evaluated and simulated in detail. These experiments were designed to offer students comprehensive knowledge of how to complete a scientific research project, from experimental design to data analysis. During the project, students improved their laboratory skills and possess a deep understanding of electrochemical analysis and cell biology.