A Portable Microfluidic System for the Detection of Health Biomarkers in Grapes at the Point of Need

In this work, a portable microfluidic system for the detection of azelaic acid (AzA) is presented. AzA is a key signaling molecule produced by plants as part of their immune response towards fungal and bacterial infections. Monitoring AzA in the field could allow for early detection of infections in crop plants with significant economic and social impact. The proposed system optically detects AzA by monitoring the kinetic behavior of the enzyme Tyrosinase, which is immobilized on microbeads trapped in the microchannel. In the miniaturized system, the microfluidic structure is coupled with custom, microfabricated thin-film silicon photosensors for signal transduction. The photosensor signal is fed to a custom amplification circuit and a microcontroller for processing. It is demonstrated that it is possible to distinguish healthy from infected vines by monitoring the AzA content.