Microfluidic Dielectrophoretic Platform for the Manipulation of Brucella abortus Bacteria: Toward Rapid Diagnostic...

Brucellosis is a neglected zoonotic disease that continues to impact global public health and livestock economies, particularly in regions with limited diagnostic infrastructure. Its causative agent, Brucella abortus, is difficult to detect due to its intracellular lifestyle and the nonspecific symptoms it causes in humans. This study demonstrates the experimental application of dielectrophoresis (DEP) in a microfluidic device for the selective manipulation of polystyrene beads and inactivated B. abortus bacteria. By tuning the frequency and medium conductivity, reliable combined negative dielectrophoretic (nDEP) and hydrodynamic flow responses were achieved, leading to the deflection of bacterial cells across the microchannel within a critical vertical window for particle control. Distinct particle trajectories were observed under varying electric field conditions, confirming effective separation without the need for labels or biochemical markers, except for visual validation. This label-free strategy enables rapid sample processing and has the potential to be integrated into portable platforms for on-site diagnostics. The results highlight the feasibility of DEP-based approaches for pathogen separation and support their future implementation in brucellosis surveillance and point-of-care testing.