Synthesis and Bio-application of Au,Ag Nanocomposites Based on Fe3O4
Supervisor:ren lei zhou zuo
-Since nanocomposites has multifunction and many properties that come from various kinds of nanomaterials,they can overcome many defects of mono-nanomaterial,such as poor biocompatibility,easily aggregation and weakly surface paintability.The composite nanoparticles of Au,Ag and iron oxide have shown a lot of excellent performance in magnetism,optics,biocompatibility,chemical stability,paintable surface,thus,nanocomposites have been considered to possess potentially broad application in the field of multifunctional imaging,bio-detection,bio-sensing,drug delivery,early diagnosis and therapy.At present,designing and synthesis composite nanoparticles of iron oxide and noble metal are great hotspots in the field of nano-biology and nano-medicine.In this thesis,we have designed and synthesized several kinds of composite nanoparticles of Au,Ag and iron oxide with different structures,presented a new method for preparing Ag-F3O4 nanocomposites by etching,and explored their formation mechanism,the relationship between structure and properties,as well as the potential multifunctional application in biology and medicine.The main contents are as follows:(1)We chose Au seed-induced growth methods to prepare Fe3O4/Au cluster/shell nanocomsites based on the multi-cores Fe3O4 clusters,and confirmed the good performance in magnetism and optics by various characterization means.In experiment,we regulated and controlled the surface profile and size of Fe3O4/Au cluster/shell nanocomsites by changing the parameters.In comparison to mono-core Fe3O4 nanoparticles,we have demonstrated several advantages of multi-cores Fe3O4 clusters in magnetism and MRI,as well as illustrated the mechanism of strengthening the magnetic resonance imaging.(2)Based on the as-prepared Fe3O4/Au cluster/shell nanocomsites,we have explored the multifunctional application in SERS(surface-enhanced Raman spectroscopy)detection for PSA,MRI and magnetic hyperthermia.The results revealed that the LOD of Fe3O4/Au cluster/shell nanocomsites was 0.75 ng mL-1 the MR imaging effect for tumor cells was desired,and the magnetic hyperthermia with nanocomposites had outstanding performance for killing tumor cells.(3)With the in situ growth method,we have prepared another kind of Fe3O4/Au nanocomsites for magnetism induced targeted MRI/PA dual-mode imaging.The results revealed that the as-prepared Fe3O4/Au nanocomsites have excellent magnetism and optics properties,and the performance of MRI/PA dual-mode imaging was great.The experiment of tumor model in living mice has confirmed that these nanocomposites had good targeted property,which observably improved the imaging effect in tumor site.(4)We have come up with a new method for preparing Ag-Fe3O4 nanocomposites with etching.This new method had many advantages,such as convenience,high efficiency,reacting at room temperature.The product had satellite-like structure,and showed uniformed size distribution,good stability,superparamagnetic property and well optics,which was of great potential for MRI and SERS detection.