Manu Sebastian Mannoor, Graduate student
Mechanical and Aerospace Engineering, Princeton University
The fundamental question we are trying to answer is whether we can directly interface highly sensitive sensors based on nanomaterial graphene with biological materials, such as tooth enamel and skin. Further, we have investigated the capability of such bio-interfaced sensors to demonstrate on-body, real-time monitoring of disease causing pathogens.
We fabricate our sensors in the dust-free environment of a clean-room facility. We do the characterization of devices using various hardware and equipment in our lab. We also do our electrical sensing measurements in a lab where we can prepare the required chemicals and biological materials.
We were able to demonstrate that highly sensitive sensors constructed using a nanomaterial called graphene can be directly interfaced with biomaterials such as tooth enamel and skin. We functionalized such sensors with biomolecules called peptides to specifically recognize and detect bacteria (such as E. coli) with a sensitivity of single cell level. Further, integration of a coil antenna to the tooth mount sensors enabled it to operate in a battery-free, wireless manner to monitor and detect stomach cancer causing bacteria present in the saliva in real-time. This demonstrates the possibility of providing on-body health quality monitoring. We also integrated such sensors with hospital equipment to monitor staph aureus “superbugs”, demonstrating the possibility of providing hospital sanitation monitoring.
The challenges that remain include: 1. Improving the selectivity of the sensor towards specific bacteria
2. Shrinking the size of the sensor with the wireless component to fit a human molar. (The image shows our sensor on a cow’s tooth.)