Zoom Link: https://hku.zoom.us/j/91034052349
Abstract
With ultrahigh photostability, nanoscale size and good biocompatibility, fluorescent nanodiamonds containing nitrogen-vacancy (NV) centers are promising nanoscale markers. The prevailing method of using this marker—quantum sensing—demonstrates outstanding function as detecting various physical quantities with high precision and spatial resolution. However, the complexity of apparatus and manipulation currently limit this method in the stage of model application and proof-of-concept. To balance strong function with ease of use, we proposed another approach, i.e., optical linear polarization modulation (LPM). In the initial phase, we set up a custom-built confocal microscopy system that provides high-quality, single-spot measurement data with user-friendly operation. Using this system, we measured the LPM curve of single NV centers to determine their orientations, and for the first time, directly observed rotational motion in the cellular traction force field—serving as a proof-of-concept for our method. In the subsequent phase, we enabled significantly brighter fluorescent nanodiamonds, by demonstrating that the LPM model of multiple NV centers is equivalent to that of a single NV center. This breakthrough allows for the observation of spatial mapping information using convenient wide-field microscopy. These advancements provided the basis for multidimensional encoding of anti-counterfeiting labels, achieving both satisfactory anticounterfeiting and commercial performance. This work marks a significant step toward the practical application of fluorescent nanodiamonds.
Speaker
Mr. Lingzhi Wang
Department of Electrical and Electronic Engineering
The University of Hong Kong
Speaker’s Biography
Lingzhi Wang received his B.Eng. Degree from Nanjing University. He is currently pursing a PhD degree in the Department of Electrical and Electronic Engineering, The University of Hong Kong. His research focuses on promoting practical application of fluorescent nanodiamonds by optical polarization modulation method.
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