Reversible Fluorescent Switching Probe Based On Polyoxometalates/QDs Nanostructures For Bioimaging

Fluorescence imaging technology has been increasingly used to monitor theactivity of cells in vivo for its low cost, simple, fast and effective detection onliving organisms.preparation of high performance fluorescent probe is key forfluorescence imaging. Development of fluorescent probes mainly experienced thisfollowing process: small organic fluorescent dyes quantum dots Lanthanidecomplexes probe fluorescence upconversion nanoparticles and reversiblephotoswitch fluorescence probe. The reversible photoswitch fluorescence probe hasbecome one of the most potential class of probes in medical diagnosis and treatmentfor its long fluorescence lifetime no background interference and high resolutionimaging.In this thesis， based on reversible photochromic properties and uniquefluorescent properties of quantum dots，we first synthesized silicon liposomes withP₈W₄₈and CdSe@CdS inside them，then wrapping silica outside it to form silicananoparticles fluorescence probe. P₈W₄₈and CdSe@CdS quantum dots inside thesilica nanoparticles occurs fluorescence resonance energy transfer then fluorescencequenching at the certain time and the certain intensity of UV light. The fluorescenceof nanoparticles recovered around95%or more after irradiated by visible light. ByModified β-actin antibody onto the surface of silica nanoparticles, the resultsshowed the fluorescent probe can be uptaken into cells.