Integrating magnetic swimmer with fluorescent color centers

Abstract

Nitrogen vacancy (NV) centers in diamonds are of current interest as quantum sensors, single photon sources, and biological nano-materials due to their unique optical and spin properties, bio-compatibility, and robust structure. Though NV center in diamonds demonstrates longer coherence time and have been used for more sensing and quantum operations compared to nanodiamonds (NDs), the prospect of selecting NDs with single, few, or multiple NV centers and moving the ND to the location of interest makes NDs suitable for various applications, due to which there is a significant boost in the last decade to manipulate and position the ND on the surface or to achieve dynamic control in the fluidic environment. We first describe the experimental setup designed to work with nanodiamonds, which was employed to measure temperature increases resulting from the Thermoplasmonics effect. This same setup was integrated with a hyperthermia system to study localized heat generation using magnetic hyperthermia. A central focus of this thesis is addressing the challenges associated with nanodiamond manipulation techniques. We developed a platform that enables the manipulation of a single nanodiamond, containing either a single NV center or an ensemble of NV centers, using a helical magnetic swimmer. In this work, nanodiamonds are attached physically to magnetically maneuverable helical swimmers and used to manipulate and position nanodiamonds. Nanodiamond properties are not affected when attached to the magnetic swimmer system. We demonstrate that the ND-swimmer can be used to sense magnetic field and temperature in a liquid environment. We show the integration of the ND-swimmer system into the biological environment, which opens up the possibility of doing spatial and temporal maps of intracellular processes. Finally, I talk about some other setups and simulations as a part of my research work: The darkfield setup was used to characterize scattered signals from nanoparticles and COMSOL Simulations to understand the behavior of metal-dielectric particles in optical confinement. In conclusion, this work combines quantum-sensing nanodiamonds with nanorobotics, creating a versatile platform for advanced microfluidics and biophysics research applications