Block Copolymer Self-assembly For Fluorescence Super Resolution Imaging

Optical nano-imaging technology is terms as optical imaging methods which are adopted to break the optical diffraction limit to observe the objects. It is currently considered as the most promising and valuable imaging technique in this century. This dissertation firstly reviews the applications and shortcomings of the single molecule fluorescence microscopy technology and characterization methods for conventional nanostructure. Meanwhile,the application of the optical nanoimaging, the synthesis and the morphology characterization of the nanostructure materials are discussed. By using photoswitchable fluorophores, the optical method breaks the resolution limit of the traditional optical microscope, which indicates that the nanostructures of chemical materials can be observed by the optical method.In this dissertation, nanostructures, such as micelles and vesicles, are obtained via self-assembly of the amphiphilic block copolymer through solvent evaporation procedure. The photoswitchable fluorophores based on hydrophobic group spiropyran(SPTS) and hexaarylbiimidazoles(NI-N-HABI) were introduced, which are embedded in the hydrophobic core t of PSt-b-PEO block copolymer. The results suggest that the combined system can form different morphologies, and the morphologies and sizes of these nanostructures are characterized by optical nanoimaging. Furthermore, we elucidated that the obtained sizes and morphologies from the method of optical nanoimaging were well consistent with the results confirmed by scanning electron microscopy(SEM) and transmission electron microscopy(TEM).The block copolymer micelles(PSt-b-PEO) containing SPTS are irradiated by 405 nm and 561 nm lasers alternatively and they indeed showed a switching behavior. After the calculation via the reconstruction method, the acquired resolution of the micelles indicates 50 nm. Compared with the traditional optical microscope imaging, the diameter of the block copolymer micelles is less than 6 times, which is closer to the actual micelles diameter. It is almost identical in comparison with the SEM or TEM results, suggesting that the static optical super-resolution imaging can be achieved.In order to trace the formation of micelles, we develops a new method of the single wavelength to control optical nanoscale imaging, using 405 nm laser to stimulate the block copolymer micelles(PSt-b-PEO)and films containing NI-N-HABI. The dynamic process of micro/nano-structures can be gained by the superresolution images at 49-nm resolution...