Promising label-free trapping, isolation and detection of extracellular vesicles, using an interdigitated microelectrode array integrated in a microfluidic cell: theoretical and experimental assessments

Abstract

Extracellular vesicles (EVs), particularly small EVs (sEVs) ranging from 30 to 150 nm in diameter, are increasingly recognized for their diagnostic and therapeutic potential. However, their broad size distribution and low abundance pose significant challenges for efficient isolation and analysis, especially in microfluidic platforms. Recent innovations in microfluidic chip design have shown promise for compact, high-throughput EV processing. Among these, dielectrophoresis (DEP) has emerged as a powerful technique for label-free EV isolation, offering high specificity, tunable electric field control, and minimal physical damage to vesicles. In this study, we developed a DEP-based microfluidic platform integrating microelectrode arrays (MEA) with interdigitated electrodes (IDE) to isolate milk-derived sEVs. Dynamic light scattering (DLS) measurements confirmed an average particle size of 133.3 +/- 7.6 nm and a zeta potential of - 23.2 +/- 0.4 mV, consistent with nanoscale classification and literature benchmarks. Finite element simulations of the electric field and particle trajectories predicted a trapping efficiency of similar to 70 under a Voltage of 7 V at 5 kHz. Experimental validation confirmed selective capture of EVs within this field range, with size-selective behavior aligning closely with simulation data.