Multispectral Capacitance Imaging of Single Red Blood Cells: Experiments and Simulations

Single-cell impedance cytometry is a powerful, label-free technique for characterizing the cells in microfluidic systems. This study investigates high-frequency capacitance cytometry of single red blood cells (RBCs) using a nanoelectrode array (NEA) sensor fabricated in complementary metal oxide semiconductor (CMOS) technology. Firstly, we evaluate the fidelity of a few RBC morphology models to an accurate reference. Then, we use the most accurate model to calculate the expected NEA response to RBCs, and we compare it with first-of-their-kind, measured, spectrally resolved RBC capacitance images. The good agreement found validates the predictive power of the cell model and suggests simple physical interpretations of some features of the experimental images. Lastly, we discuss the perspectives for non-invasive probing of the intracellular properties of single RBCs, considering cytoplasm conductivity variations comparable to those found in erythrocytes infected by the malaria parasite.