Rapid Multianalyte Microfluidic Homogeneous Immunoassay on Electrokinetically Driven Beads

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Microfluidics

Background:

• Homogeneous immunoassays offer rapid diagnostics for acute conditions due to simplified procedures.
• Microbeads enhance analyte capture and material aggregation for improved readout in standard assays.
• Acute kidney injury (AKI) diagnosis requires timely detection of biomarkers like NGAL and Cystatin C.

Purpose of the Study:

• To develop an integrated microfluidic system for rapid, simultaneous detection of AKI biomarkers.
• To utilize dielectrophoretic (DEP) forces for controlled bead manipulation and analyte capture.
• To achieve on-chip analyte detection and biomarker quantification within a short timeframe.

Main Methods:

• Development of a microfluidic chip with integrated 3D electrodes for dielectrophoretic (DEP) manipulation of antibody-decorated microbeads.
• Application of DEP forces to retain beads against reagent flow for efficient on-chip analyte binding.
• Utilizing size-specific electrokinetic forces to direct different bead populations to distinct readout regions for multiplexed detection.

Main Results:

• Demonstrated efficient retention of antibody-decorated beads against fluid flow using DEP forces.
• Achieved concomitant analysis of Neutrophil Gelatinase-Associated Lipocalin (NGAL) and Cystatin C in serum within 15 minutes.
• Successfully directed differently decorated beads to separate readout zones, enabling multiplexed biomarker detection.

Conclusions:

• The integrated microfluidic system enables rapid, simultaneous detection of AKI biomarkers NGAL and Cystatin C.
• The use of DEP forces allows for efficient bead manipulation and on-chip analyte binding and separation.
• This technology holds promise for the rapid diagnosis of acute, life-threatening conditions.