Author: Drew

This project aims to integrate CMOS electronics with a versatile single molecule detector, the nanopore. Biomolecules, such as deoxyribonucleic acid (DNA) or proteins, can be guided through a nanoscale aperture (referred to as a nanopore) one molecule at a time, resulting in signatures that reveal characteristics of the passing molecule. As single-stranded DNA translocates through a nanopore, each nucleotide induces a blockage in the ionic channel, creating a unique current signature. However, the fast translocation speed of 1-10 nucleotides per microsecond and small current changes of 1-10 picoampere, which are superimposed on a much larger baseline current of 1000 picoampere, pose significant technical challenges on the measurement circuitry design. In the Hall group, we are researching how to design low-noise and high-speed transimpedance amplifiers to sense these minute current signatures. An inexpensive single molecule biosensor will have a tremendous impact in areas as diverse as medicine and health, both domestically and abroad.

With a significant increase in the availability of portable and network connected devices over the last few decades, the infrastructure already exists to be able to integrate medical diagnostic tools with mobile technology. Taking advantage of this opportunity, the Hall research group is working on developing low-cost, point-of-care (POC) biosensor devices, which allow users to test biological samples, analyze data, and aggregate the results for study by medical professionals all without the need for a centralized laboratory or bulky and expensive equipment. There are several projects currently in progress that fall under the umbrella of mobile Health (mHealth).

With the focus on leveraging the functionality and widespread use of the smartphone, especially in developing countries, we are designing two versions of a low-cost smartphone-based biosensor. The first is a low-power, single-channel potentiostat to be used for electrochemical assays and the second is a wireless, multiplexed version with added sensors. We are also working in partnership with industry to integrate biosensor modules directly with smartphone hardware. On the transducer and bio-chemistry side, we are investigating novel methods of functionalizing electrodes that decrease the cost per disposable test strip making these POC devices more practical. Finally, the compact and low-cost nature of electrochemical techniques has allowed us to combine our electrochemical biosensors with optical biosensors for improved detection on Lab-on-Chip type devices.