Collaborative Research: Waveguide-Integrated Graphene Nano-tweezERs (WIGNER) for rapid sorting and analysis of nanovesicles and viruses

Nontechnical description: This project aims to design and demonstrate a sensing platform which incorporates recent advances in both electrical trapping and integration of optical circuits for rapid concentrating, sorting, and analysis of biological nanoparticles. Viruses and cellular fragments extracted from liquid samples of a patient (e.g., urine, blood, etc.) contain abundant diagnostic information which can be used to detect and treat many diseases. However, detecting a specific target bioparticle from a mixture of many other particles in the sample complicates diagnostics. Current methods for isolating the targe bioparticles often require time-consuming processes such as multiple filtering or centrifugation stages, followed by amplification. Therefore, an active biosensor which rapidly sorts, traps, and detects bioparticles based on their size and physical properties would have significant impact on the field of biosensing and medical diagnostics. Mass producing such sensors could reduce the complexity, cost, and delay for patients undergoing medical diagnostic tests. This project also provides mentoring and outreach opportunities for undergraduate and high school students who are underrepresented in STEM fields.Technical description: This project will develop a biosensor which can sort, trap, and detect extracellular vesicles (EVs) and viral specimens by combining highly confined evanescent field excitation from visible waveguides with dielectrophoretic (DEP) trapping using atomically sharp graphene electrodes. To demonstrate this Waveguide-Integrated Graphene Nano-tweezERs (or “WIGNER”) platform, the team will: 1) combine transparent DEP graphene electrodes and silicon nitride photonic waveguides; 2) integrate microfluidics for efficient aqueous nanovesicle sorting and trapping; and 3) demonstrate rapid detection and analysis of single nanovesicles and viruses using line-imaging optical scattering, fluorescence, and Raman spectroscopy. The project aims to enable physiologically selective, multimodal analysis of nanovesicles and viruses at speeds ~100× faster than conventional scanning methods (i.e., confocal fluorescence and Raman spectroscopy). Project outcomes will have immediate relevance for emerging applications in life sciences (e.g., elucidating cell signaling pathways), nanomedicine (e.g., dynamic antibody binding response to lipid membranes used in mRNA vaccines), and disease diagnosis (e.g., amplification-free viral detection).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.