Multi-Scale Optical Metrology of Biomaterials and Nanomaterials for Medical and Industrial Applications
- Author(s): Reiber Kyle, Jennifer Lynn
- Advisor(s): Ozkan, Mihrimah
- et al.
Nanotechnology is a promising field that is focused on working at the atomic and nanoscale. Many helpful materials and imaging techniques have been developed in nanotechnology. Graphene, a nanomaterial consisting of a single atomic layer of carbon atoms arranged in a hexagonal lattice, exhibits excellent optical, electrical, and thermal properties and has many applications in the semiconductor, energy, and thermal management industries. Additionally, iron oxide nanoparticles are excellent candidates for drug delivery and labeling applications in medicine due to their high biocompatibility and customizable size and surface chemistry. Near-field microscopy is a nanoscale imaging technique with the capability of providing the label-free tissue diagnostics medical field with information about the intrinsic optical properties of tissue that cannot be probed by any other techniques. Despite the benefits that near-field microscopy offers for medicine, its use in imaging biomaterials has been limited due to the large topographic variations that these samples exhibit. This gap between the nanoscale and the scales of interest for industry and medicine also presents an obstacle in the application of iron oxide nanoparticles in medicine and graphene in industry. In this work, I develop multi-scale optical metrology techniques for characterizing graphene at the industrial scale, identifying unlabeled nanoparticles within cultured human cells, and studying the intrinsic optical properties of tissue with near-field microscopy. Through fluorescence quenching microscopy (FQM), I map the layer thickness and uniformity of entire centimeter-scale graphene sheets and identify fluorine-doped regions. I utilize scanning near-field optical microscopy (SNOM) to identify iron oxide nanoparticles in cultured human cells through their scattering behavior, and I develop SNOM for label-free tissue diagnostics, quantifying image creation in SNOM of large biological samples and then revealing the cause of scattering dependence on the hydration state of fixed human breast tissue. This work contributes knowledge to the graphene growth, nanoparticle design, and label-free tissue diagnostics fields and facilitates the integration of nanotechnology with medicine and industry.