SUPER RESOLUTION IMAGING AND NANOSCALE MAGNETIC DETECTION IN MICROFLUDIC DEVICE.

Abstract

Nanoscale sensing and imaging tools are the most emerging techniques in fields of nanoscience research and engineering. To demonstrate nanoscale sensing and imaging tools, it is required to achieve high sensitivity and spatial resolution simultaneously. By fulfilling the requirements, this thesis describes mainly two different scanning applications employing quantum probes and nanoparticle positioning technique using fluid flow control.

First, we develop a method that can systematically probe the distortion of an emitter’s diffraction spot near a nanoparticle in a microfluidic device. The results provide a better fundamental understanding of near-field coupling between emitters and nanophotonic structures. We demonstrate that by monitoring the distortion of the diffraction spot we can perform highly accurate imaging of the nanoparticle with 8 nm spatial precision.

Next, we develop a method to perform localized magnetometry in a microfluidic device with a 48 nm spatial precision. We map out the local field distribution of a magnetic nanoparticle by manipulating it in the vicinity of an immobilized single NV center and optically detecting the induced Zeeman shift with a magnetic field sensitivity of 17.5 μT Hz-1/2.

Finally, we introduce a scanning magnetic field technique that employs multiple NV centers in diamond nanocrystals suspended in microfluidic channels. This technique has advantages of short acquisition time over wide-field with nanoscale spatial resolution. The advantages make our technique attractive to a wide range of magnetic imaging applications in fluidic environments and biophysical systems.