Synthesis And Application Of Ruthenium 1,10-Phenanthroline-based Nano-Composite Materials In DNA Detection

Compared with the conventional organic molecular fluorescent probes,ruthenium 1,10-phenanthroline-based luminescence probe exhibits unique properties such as excellent photochemical stability,large Stokes shift,low toxicity,good water-solubility and long phosphorescence lifetime.Silica-based materials have drawn worldwide attention in the past decades due to their unique properties,such as periodically aligned pore structure,easy modification,high surface area and good biocompatibility.Carbon dots(CDs)is a kind of emerging zero-dimensional carbonaceous nanomaterials,which has low cytotoxicity,excellent biocompatibility,good resistance to photobleaching,stable emission and easy modulation.In this thesis,we studied the silicon-based and carbon-based nano composite materials based on ruthenium 1,10-phenanthroline.Mesoporous silica nanoparticles were prepared via ammonia-catalyzed hydrolysis and condensation of ethylsilicate(TEOS).The positively charged ruthenium(?)complexes were loaded on negatively charged MSNs by electrostatic interactions,obtaining MSNs–Ru composite.MSNs–Ru composite entered cells through endocytosis,completing the imaging of intracellular DNA based on the interactions between ruthenium(?) and DNA.Cell imaging results indicated that significant luminescence can be observed for the group incubated with MSNs–Ru composite.However,there was almost no luminescence for the group incubated with ruthenium(?) under the same culture time of 3h.DNA could promote the F?rster resonance energy transfer(FRET)process between CDs and ruthenium(?) complexes,resulting in the ratiometric fluorescence intensity changes of CDs-Ru.Herein,a FRET-based ratiometric emission probe(CDs-Ru probe)was developed for the determination of DNA with high sensitivity and selectivity.The detection limit of Calf Thymus DNA(CT DNA),Human Immunodeficiency Virus(HIV)were 5.36×10-8 g mL-1 and 1.38×10-8 g mL-1,respectively.