Research

Please visit the above links to have a more detailed look at our research projects. Below is a list of Centers that we are leading or affiliated with.

NSF STC EBICS at MIT/GT/UIUC - Emergent Behavior of Integrated Cellular Systems

NSF IGERT at UIUC - Cellular and Molecular Mechanics and Bionanotechnology
(download brochure)

NIH Training Grant at UIUC - Midwestern Cancer Nanotechnology Training Center
(download brochure)

NSF CiiT (I/UCRC) at UIUC - Center for Innovative Instrumentation Technology

NSF NSEC at OSU - Center for Affordable Nanoengineering for Polymeric Micro and Nanodevices

 

Research:

Improving the sensitivity of field effect biosensors through electronic desalting

Direct molecular sensing in nano-biosensors facilitates a label-free electrical detection route, which greatly simplifies the diagnostic instrumentation, useful for point-of-care applications and resource-limited settings. Nanowire-based FET devices have shown potentially very high sensitivity for detection of small biomolecules, such as nucleic acids, proteins, and viruses. FETs being highly scalable, they are ideally suited for miniaturizing the diagnostic platform. However the inability to commercialize these sensors is largely because we cannot sense directly from blood or serum due to shielding of molecular charge by the excess of ions. Screening by background salt ions interferes with sensing from physiological media by decreasing the apparent charge at the sensor and reducing the overall sensitivity. Our goal and design is an electronic desalting scheme, using on-chip polarizable electrodes around a FET that locally deplete the salt ions to overcome shielding, that improves the sensitivity to detect bound molecules (e.g., miRNA cancer markers). By overcoming ionic shielding, charge transduction to the FET and, consequently, the sensitivity can be maximized. The on-chip electrodes also gate-bias the FET for simultaneous sensing during desalting, to beat the competing back-diffusion of the salt ions. The entire sensor is miniaturized to the sub-nanoliter scale of a FET-in-a-droplet, which can pave the way for multiplexed electronic detection with high sensitivity from physiological media.


Fig. Schematics of FET biosensor with on-chip desalting within a droplet using polarizable electrodes, and improved detection scheme, providing enhanced sensitivity upon localized desalting

 


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