Student Design Competition – Impedance-Based Point-of-Care Biosensor

Abstract

An impedance-based Point-of-Care biosensor has been designed. Using interdigitated electrodes and signal-enhancing gold nanoparticles, a variety of different biological molecules can be detected by the system. The sensor hardware was designed with an emphasis on portability, affordability, and versatility. These characteristics make this sensor system well suited for deployment in remote areas or low-income countries. Utilized as an early detection system for disease screening, or remote monitoring of medical health, this low-cost system could save money, and much more importantly, lives. The POC sensor system is made up of disposable interdigitated gold electrode chips which are modified with molecular recognition elements (MREs), such as antibodies, signal-enhancing gold nanoparticles, and a handheld impedance measuring sensor. When a biological sample (blood, urine, etc.) is introduced onto an electrode, the target biomolecule binds to the MRE on the electrode, which in turn binds a gold nanoparticle to the surface. These nanoparticles have an effect on the electrical properties of the electrode which can be measured as a concentration value by the sensor. The biosensor system can be connected to a smart device using Bluetooth technology. An app on the connected device can control the system and output results. This demo consists of the portable impedance sensor, the control and display app used with a smart device, and the microfabricated electrode chips used for sensing.