Integrated dielectrophoresis and fluorescence-based platform for biomarker detection from serum samples

Early diagnosis is key for successfully treating many life-threatening diseases, such as cancer. Traditional diagnostic techniques, such as enzyme-linked immunosorbent assay, often fail or are not capable of detecting molarities in the early stages of disease progression. To address this unmet need, we integrated dielectrophoresis and fluorescence in a single device and utilized them to detect biomarker molecules. Prior to detection, target biomolecules were immobilized on polystyrene bead surfaces and fluorescently labeled. We then used the dielectrophoretic force to concentrate beads on specific areas within the device and measured the fluorescence intensity of the sample. To demonstrate the detection of biomolecules, we have used the technique to quantify avidin molecules in human serum samples. We have found that the measured fluorescence is proportional to the molarity of avidin molecules. Our results also indicate that this technique can detect pM molarities within about 15 min. Therefore, our technique has great potential for use in the detection of early stage of disease progression.