Over the past several years, microfluidic devices have shown extraordinary potential in the area of diagnostics with potential utility for resource-limited areas and epidemic biosurveillance.
At the Ecole Polytechnique Fédérale De Lausanne (EPFL) research organization in Lausanne, Switzerland, a new type of microfluidic platform has come out of the Laboratory of Biological Network Characterization (LBNC), headed by Sebastian Maerkl. The portable device runs on battery power, is completely self-sustained, and operates seamlessly with inexpensive microscopes to provide very high levels of accuracy and detection.
The platform, which is described in a recent ACS Nano article, can quantify up to 16 different molecules – or biomarkers – in a tiny amount of blood (less than 0.005 milliliters). The biomarkers are usually enzymes, proteins, hormones or metabolites and the concentration of these molecules in the blood provides precise information on the patient’s health condition.
The low-cost device has already been tested on Ebola and can be used to detect many other diseases. “The platform will lead the development of new kinds of tests to meet the increasing demand for on-site diagnostic testing. It will prove very useful for medical staff working in resource-limited regions,” said Francesco Piraino, the article’s lead author.
The research team found that they could load blood samples directly onto the device and perform on-chip biomarker quantitation without requiring any sample pre-treatment. “For researchers, it is quite interesting to be able to avoid having to separate the blood,” said Francesco Piraino, the article’s lead author. Blood plasma separation requires centrifuges, large volume samples and a long processing time.
The device also unique in that it is composed of both analog and digital detection mechanisms, while conventional devices hitherto only integrated one or the other. Digital detection is highly sensitive and can detect the presence of a single biomarker. However, it is less effective when the concentration of biomarkers is too high, due to signal saturation.
Analog measurements, on the other hand, function best at higher biomarker concentrations. Using these two detection mechanisms simultaneously, the composition of a drop of blood can be thoroughly analyzed in a short amount of time. The analysis provides precious medical information: it could help doctors make an early diagnosis or determine the stage of a disease.
