Nanoscale field-effect transistors represent a unique platform for real-time detection of biochemical and bioelectrical signals with unprecedented sensitivity and resolution, yet their translation toward applications under physiological conditions remains challenging. The goal of the project is to develop a hybrid sensing platform to overcome the intrinsic limitations of traditional field-effect transistor design by incorporating functional hydrogels as the interfacing material. The proposed sensor design not only provides a true biocompatible microenvironment for long-term, reliable molecular and cellular integration, but also enables the application of existing nanoelectronic toolsets in physiologically relevant conditions, thus allowing for new insights into many biologically significant processes. The proposed studies will impact positively on many aspects of public health by providing new opportunities in point-of-care diagnostics, in-vitro/in-vivo monitoring of disease progression, and clinical brain-machine interfaces. Furthermore, the investigators will emphasize the interdisciplinary link between advanced technology and the natural sciences to broaden STEM participation through summer internship, with special focus on underrepresented high-school students from local community.
The overall objective of this proposal is to develop a hybrid nanoelectronic interface composed of graphene field-effect transistors and spatially-defined functional hydrogels for improved bioelectronic transduction at both the molecular and cellular levels. In particular, targeted photopolymerization will be exploited to achieve selective placement and design of biocompatible hydrogels on top of individual transistor devices to integrate the nanoelectronic and biological functionalities onto a single, multifuntional platform. At the molecular level, bio-specific receptors will be sequentially encapsulated into the hydrogel gate to independently encode device selectivity for multiplexed molecular detection with high spatial resolution while reducing Debye screening and non-specific binding, and extending shelf-life. At the cellular level, surface-initiated nanometer-thick hydrogel will serve as photosensitive adhesive to establish robust, minimally-invasive cellular interfaces. Such intimate proximity will enhance coupling of bioelectronic signals with the underlying graphene channel. The ability to pattern and electrically communicate with individual cells enables the rational design of large-scale, addressable transistor/cellular arrays that will provide high-spatiotemporal resolution studies of bioelectrical and biochemical signal propagation at both single cell and biological network levels. The proposed research represents a new approach to achieve seamless integration of biological components with electronics, and is expected to provide a significant improvement over current state-of-the-art techniques by allowing to access elusive biological signals and emerging bioelectric phenomena and providing a substantial increase in data availability and information.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.