Controlled Fabrication of Nanoscale Dielectric Waveguides for Single Molecule Spectroscopy at High Concentrations
Authors: Cristian A. Rodriguez, Daniel Castro
Faculty Supervisor: Huizhong Xu
Department: Physics & Astronomy
Fluorescence Correlation Spectroscopy is a powerful technique for examining particle concentration fluctuations within small volumes, typically around one femtoliter. While this small excitation volume is sufficient for examining the dynamics of a single molecule in the nanomolar range, it falls short for cell membrane processes that typically involve micromolar concentrations and require a sampling volume on the order of 100 zeptoliters. In this study, we introduce a new method that employs a dielectric nanowire waveguide to achieve a sampling volume of about 170 zeptoliters as a result of an illumination spot that is confined to 50 nanometers laterally and 20 nanometers longitudinally. We use two different nanofabrication approaches to fabricate these dielectric nanowire waveguides, and the results will be presented.