A new sensor designed by MIT is meant to help doctors and caregivers in hospitals to more quickly diagnose a condition that kills 250,000 people annually. The condition is sepsis, and the quicker treatment can start, the more likely those affected by sepsis can begin to get better. Sepsis is when the immune response to infection triggers an inflammation chain throughout the body leading to high heart rate, high fever, shortness of breath, and other issues.
When left untreated for too long, sepsis can lead to septic shock where blood pressure drops and organs shut down. MIT researchers have a microfluidics-based system that can automatically detect clinically significant levels of IL-6 for a sepsis diagnosis in about 25 minutes. IL-6 (interleukin-6) is a protein produced in response to inflammation and in people with sepsis levels can rise hours before symptoms show.
One of the microfluidic channels of the device has microbeads laced with antibodies that mix with a blood sample to capture the IL-6 biomarker. Another channel has only beads containing the biomarker attach to an electrode. A voltage is run through that electrode that produces a signal from each biomarker-laced bead that can be converted to a biomarker concentration level.
Systems to detect biomarkers are available now but rely on optical components, making them expensive. The MIT team wanted to shrink the device down and design an automated microfluidic device that is small at several square centimeters. The beads inside the device are coated with an antibody that attracts IL-6 and a catalyzing enzyme called horseradish peroxidase.
Once the blood sample is injected into the device, in about ten minutes, many beads have stuck to the electrode coated with a sperate antibody that attracts IL-6. When that happens another fluid washes away the untethered beads and those with IL-6 remain on the electrode. All the medical staff has to do is load in a blood sample with a pipette and press a button, 25-minutes later they have an IL-6 concentration.