Fluorescent Spectrum Imaging And Scattering Imaging Of Single Quantum Dots

As a new class of fluorescence probes, quantum dots have many excellent optical properties, compare with traditional fluorescence dyes, and play more and more important roles in the fields of molecular biology, cell biology and medicine, et al.. These thesis give an overview on quantum dots, about their optical properties, preparation, modification and applications in single molecule detection; Major study of the experimental is mainly carried out the following two areas: multicolor quantum dot imaging at the same time and scattering imaging of single quantum dot:1 Single-channel imaging of two-color quantum dot. A kind of excitation light can stimulate a variety of quantum dot luminescence, if bio-molecular tag different QDs, interactions of biological molecules within living cells can be detected, we can real-time observe a specific receptor interaction. As the single-channel render black and white pixels, each pixel represents a gray value. Single-channel can only distinguish a light-emitting quantum dots. At present, detection of multi-color quantum dots is got by multi-channel detector. But the multi-channel light transmission rate will affect the quantum dots observations. In this paper, we distinguish two markers by measuring distance between zero level and one level with transmission grating, this single-channel imaging will help to studying the interaction between molecules.2 Scattering imaging of single quantum dot. Research of quantum dot is carried out under the fluorescent microscope, this paper achieve single quantum dot imaging by dark-field scattering. Scattering imaging will help to further study the optical physical properties of quantum dots, and provide an alternative detection method on similar size or difficult to detecting fluorescent nanoparticles. At the same time the experiment confirms that quantum dots occurr photobleaching by combining dark-field mode and fluorescence mode.