Professor Ji-Ho Park, from the Department of Bio and Brain Engineering, and his team announced that they have developed a versatile and biocompatible nanowire-based optical probe. The probe can guide visible light into intracellular compartments of a cell and detect optical signals from subcellular regions with high spatial resolution. Professor Park expects that the endoscope can be a likely candidate for high-resolution optical imaging, mapping and chemical/biological sensing, and precise delivery of gene, proteins and drugs.
Although current optical techniques have reached the subcellular level, high precision optical imaging systems are complex and expensive. By bonding a SnO2 nanowire to the sharp tip of an optical fiber, Professor Park fabricated the nanowire endoscope, which can safely penetrate the plasma membrane.
Nanowires are appropriate for negotiating intracellular environments for several reasons. Firstly, they inflict minimal damage on cellular structure and functions due to their small dimensions, uniform geometry and mechanical flexibility. Secondly, the nanowires can guide visible light efficiently in high-index physiological liquids because of their higher refractive index than that of conventional optical fibers. Lastly, because they are mechanically robust, they can endure repeated deformation, bending and buckling cycles without being peeled off the fiber.
Professor Park said, “In this research, the probe was applied to cultured cells outside the organism. Having shown that the nanowires are biocompatible, it will be used to optically stimulate and adjust specific types of cells in living organisms.”
The research was conducted through multidisciplinary cooperation; the team included Professor Seung-Man Yang and Doctor Cheoljun Heo from the Department of Chemical and Biomolecular Engineering, Professor Yeonho Choi from Korea University, Professor Peidong Yang, Luke Lee, and Doctor Ruoxue Yan.
The results were published on the December 18 online issue of the world-renowned journal Nature Nanotechnology.