Speaker: Sanghwa Jeong, Ph.D. (University of California, Berkeley)

Subject: Deep Tissue-Penetrating Optical Nanosensors of Biological Activity: Target-oriented and Diversity-oriented Approaches

Abstract

Fluorescence imaging technique has been the gold standard for sensitive molecular sensing with high spatiotemporal resolution, however the subject needs to be transparent due to limited light penetration through biological media. Recently, the wavelength channel has extended into the second near-infrared region (NIR-II; wavelength = 1000-1700 nm) providing enhanced spatial resolution through deep tissue than conventional wavelength region due to suppressed photon scattering and near-zero autofluorescence. In this talk, two different strategies to design NIR-II molecular sensors will be represented: (1) cancer-microenvironment-activatable NIR-II quantum dots by target-oriented approach based on known molecular recognition mechanism and (2) neurotransmitter-selective NIR-II carbon nanotube-DNA complexes by diversity-oriented approach following the systematic evolution of nucleic acid ligands by competitive enrichment. We further show the utility of graphene oxide quantum dot (GOQD)-polymer complexes as the potential candidate for optical sensors for neurotransmitter.