Human blood plasma and other body fluids are routinely used for identifying factors/ biomarkers for clinical diagnoses of numerous diseases. In traditional disease diagnostics, the processes of blood collection, sample preparation, detection of biomarkers, and disease diagnosis are performed separately and require expensive equipment, increasing diagnosis time anywhere from 3 days to 2 weeks. Inexpensive lateral strip tests can diagnosis diseases in less than 60 seconds, but lack the sensitivity and specify of traditional quantifiable diagnostic methods. Therefore, a microfluidic device for integrated plasma separation and sensitive multiplex biomarker detection was designed and fabricated by using soft lithography and the principle of bubble-induced acoustic energy. Plasma separation and biomarker detection occurs when an acoustic field causes air bubbles to oscillate, trapping the larger blood cells whilst more smaller plasma contents flow downstream. This Immunoessence chip has separated plasma with a 31.8% yield and 99.9% purity. Further, the cell-separation experiments were highly reproducible (100%), with no cell-clogging.

This device has also successfully been integrated with downstream detection of HIV p24 antigens. To make this rapid-test more sensitive than the currently used colorimetric immunoassays, the device utilizes a more sensitive and quantitative fluorescence-based detection system with a lower limit of detection of 17 pg/µL. The Immunoessence chip as the following advantages: 1) Inexpensive to fabricate <2$ per device 2) Portable 3) Invasive (requires less than 30 μL of blood) 4) <4 minute run time 5) Quantitative detection of biomarkers 6) Ability to be integrated with other detection and sample preparation tests

What inspired you (or your team)?

After my Aunt passed away from colon cancer when I was 10, I was left puzzled and heartbroken as to how modern-day medical facilities had failed to diagnosis her cancer at early stages. Since the age of 10, I have always been passionate about developing a diagnostic system that could perform detection of diseases at low costs to prevent future deaths.