Preparation And Properties Of Fluorescent Nanoprobe For Small Molecule

With the development of fluorescent nanoparticles, fluorescent nanoparticles(NPs) have unique optical properties, complicated surface chemistry, which can be used to fluorescence imaging and sensing as well as for in vitro and in vivo labeling in cells, tissues. Thus, fluorescent nanoparticles are widely employed in various areas of biology and medicine, including proteomic and genomic studies, disease diagnostics, pharmaceutical screening, drug delivery, assembled molecular control, protein purification, biological therapeutics, and medical imaging(such as in vivo imaging, sensing in cancer research, and selective tumor targeting). We have prepared the fluorescent nanocomposite via combing the fluorescent nanoparticle and the small nolecule or nanoparticle together to detect the small molecule. Content is as follows: 1) A highly sensitive carbon dot–imidazole(CD–imidazole) nanoprobe is prepared through covalently conjugating imidazole group onto the surface of carbon dots for water fluorescence. In organic solvents, quenching of fluorescence occurs via photoinduced electron transfer(PET) process from the imidazole nitrogen to the CD acceptor. Addition of a trace amount of water into CD nanocomposites in various organic solvents leads to a fluorescence turn-on response, which can be attributed to the suppression of PET due to the formation of the “free” ion pair by proton transfer from the carboxyl groups that are on the CDs surface to the imidazole nitrogen through a water-bridge. This phenomenon can be used for the highly selective detection of trace amounts of water in organic solvents. Laser confocal microscope experiment shows the potential utilization of CD–imidazole for the probed proton-transfer reactions in living cells. 2) MnO2-phenol formaldehyde resin(MnO2-PFR) nanocomposite is successfully prepared by a simple chemical reduction process. The resultant MnO2-PFR nanocomposite is well characterized. The absorption band of non-fluorescent MnO2 nanosheets overlaps well with the fluorescence emission of PFR nanoparticles. The green fluorescence of PFR in this nanocomposite can be effectively quenched by fluorescence resonance energy transfer from PFR to MnO2. In the presence of glutathione(GSH), the fluorescence of PFR could be recovered due to MnO2 was reduced to Mn2+ by GSH. The nanocomposite can be use for detecting glutathione in blood serum. 3) we have successfully designed and synthesized a novel nanoprobe based on fluorescence resonance energy transfer from SiQDs to MnO2 nanosheet and demonstrated its utility as a fluorescence turn-on nanoprobe which allows the selective detection of GSH in solution and in living cells. The recognition process involves that MnO2 was reduced to Mn2+ and the fluorescence of SiQDs can be recovered in the presence of GSH.