Microwell-based nDEP multifunctional microfluidic system for single-cell capture and analysis

Microfluidic systems have revolutionized biological and clinical analyses, offering precise control over fluid manipulation at a microscale. In recent years, significant advancements have been made by integrating these systems with lab-on-a-chip technologies and expanding their applicability in various biotechnological and diagnostic fields. This work presents the development of a multifunctional lab-on-a-chip device that combines microwell structures with negative dielectrophoresis (nDEP) to enable both single-cell capture and in situ single-cell analysis. The proposed device was first validated using commercially available polystyrene microparticles (beads) and human embryonic kidney (HEK) 293 cells. Impedance analysis and real-time fluorescence microscopy was used to confirm nDEP-mediated high-efficiency single-cell capture within the device's microwells. Finally, single-cell lysis was performed to demonstrate in situ analysis inside the microwells. One of the key advantages of nDEP is its ability to function effectively in physiological media, which typically has high conductivity to model in vivo conditions. nDEP is compatible with high-conductivity environments which allows for optimization across a range of biomedical and clinical studies. In summary, our device provides a platform for a low-cost, miniaturized, and automated single-cell analysis which can be adapted to numerous applications, such as single-cell sequencing, protein analysis, and electrophysiological studies.