A Versatile and Fully Integrated Hand-Held Device for Microfluidic-Based Biosensing: A Case Study of Plant Health Biomarkers

The development of a portable, Point-of-Need device to measure plant biomarkers in the field is reported. The system consists of a microcontroller-based hand-held device capable of reading photosensors at low signal levels (pA-nA) and driving light sources or pump actuators that couples to a microfluidic chip for performing colorimetric assays. The user interface is through a touchscreen and data is stored on-board in a memory card. Although robust and well-established bench-top instrumentation is available for these types of assays, many applications in the Agro-Food industry require portable systems that can make fast and inexpensive measurements in the field. We apply this system to the detection of Azelaic Acid (AzA), a known biomarker for plant health, in the nM regime. The developed system is versatile and can be applied to different types of ELISA, DNA and enzymatic based biosensing assays at the point-of-need, for plant, animal and human health applications.