Biosensing on large-scale field-effect transistor array

Biosensing on large-scale field-effect transistor array

Diagnostic techniques have become critical to modern health care not only for patient diagnosis and optimization of treatment, but also for providing vital information regarding pathways for complex diseases. Ideal biosensors provide the maximum desirable data with the least amount of complexity. However, to date, most biosensors either yield very specialized data or are very complex and expensive. Researchers have attempted to address this need with the development of point-of-care sensors that can provide accurate data without the need for expensive equipment. Semiconductor manufacturing techniques offer a particularly attractive opportunity to design a biosensor that is highly versatile; extremely inexpensive; produced with high yield, stability, and reproducibility; and highly sensitive to target analytes due to device size. Such fabrication techniques at industrial class foundries have been honed to perfection with optimization and standardization. Prototyping of new device designs in a foundry can critically enable rapid commercialization of new bio-medical platforms.

We are working with a versatile electrical biosensor platform consisting of tens of thousands of devices fabricated with silicon-on-insulator line. The platform consists of a unit cell transistor integrated seamlessly with control and read-out circuitry that is amenable for immediate commercialization. Each cell consists of a sub-micron FET Sensor with a near-Nernst pH sensitivity of around 56-59 mV/pH and a resolution of <0.01 pH. The gate oxide is directly exposed to the target analytes, instead of to the commonly employed floating gate architecture. This enables many critical advantages, including increased sensitivity due to the elimination of parasitic coupling capacitances and reduced vulnerability to crippling factors such as electrostatic discharge. The unit cell can be coupled to a variety of different surface chemistries for different target analytes and applications.


Fig. Image of a field effect transistor chip with over 16000 devices, used for biosensing applications with individual droplets. Droplets are roughly 250pL.


This material was originally published on the website of the Laboratory of Integrated Biomedical Micro/Nanotechnology & Applications (LIBNA).