The investigation of human disease mechanisms is difficult due to the heterogeneity in gene expression and the physiological state of cells in a given population. In comparison to bulk cell measurements, single-cell measurement technologies can provide a better understanding of the interactions among molecules, organelles, cells, and the microenvironment, which can aid in the development of therapeutics and diagnostic tools. In recent years, single-cell technologies have become increasingly robust and accessible, although limitations exist. In this review, we describe the recent advances in single-cell technologies and their applications in single-cell manipulation, diagnosis, and therapeutics development.

The ability to deliver foreign molecules into a single living cell with high transfection efficiency and high cell viability is of great interest in cell biology for applications in therapeutic development, diagnostics and drug delivery towards personalized medicine. Many chemical and physical methods have been developed for cellular delivery, however most of these techniques are bulk approach, which are cell-specific and have low throughput delivery. On the other hand, electroporation is an efficient and fast method to deliver exogenous biomolecules such as DNA, RNA and oligonucleotides into target living cells with the advantages of easy operation, controllable electrical parameters and avoidance of toxicity. The rapid development of micro/nanofluidic technologies in the last two decades, enables us to focus an intense electric field on the targeted cell membrane to perform single cell micro-nano-electroporation with high throughput intracellular delivery, high transfection efficiency and cell viability. This review article will emphasize the basic concept and working mechanism associated with electroporation, single cell electroporation and biomolecular delivery using micro/nanoscale electroporation devices, their fabrication, working principles and cellular analysis with their advantages, limitations, potential applications and future prospects.