Synthesis and Biomedical Applications of Multifunctional Core-Shell Plasmonic Nanomaterials

Author:Jin Xiu Long

Supervisor:ye jian


Degree Year:2018





Multifunctional nanoparticles can effectively integrate various functions as carrier,therefore,exhibit great potential in the field of bioimaging and disease treatment.Core/shell nanoparticles,due to its highly tunable function and structure,have great importance for the design of novel multifunctional nanoparticles.Based on core/shell nanostructure and continuously optimize the performance of nanoparticles,such as Surface-enhaced Raman Spectroscopy(SERS)and photothermal capacities,we have designed three kinds of novel multifunctional plasmonic nanoparticles by changing the composition and morphology of core and shell.We further studied their physical and chemical properties,and its related biomedical applications.The main research contents included three aspects:(1)The construction and biological application of novel superparamagnetic gold nanoshells(SNs).SNs can effectively integrate optical properties of gold nanoparticles and superparamagnetic of Fe3O4 nanoparticles.SNs exhibit enhanced two-photon fluorescence(TPL)bioimaging ability and manipulation capacity under external magnetic field.SNs can label cells through phagocytosis process,separate and enrich the labeled biosamples with high efficiency.SNs show good SERS performance.By introducing SNs non-specific labeling method into human umbilical vein endothelial/human fibroblast cells vascularization co-culture model,we can replace traditional immunofluorescence and magnetic beads separation methods,in-situ monitor vascularization process.SNs labeling method also gives us manipulation of cells or biosamples at some content under magnetic field.(2)The preparation of nanoplate-based gap-enchanced SERS tags(TGERTs)and its related capacities evaluation.By optimizing the integrity and thickness of Au shell coated outside,the SERS signal intensity of TGERTs can reach 40 folds of GERTs.TGERTs also show better photothermal property than GERTs.Through screening and polyelectrolyte surface modification,the obtained iii-PSS-PDDAC nanoparticles exhibit both strong SERS enhancement and good photothermal performance,and also show good biocompatibility,can effectively meet dual demands of SERS bioimaing and photothermal therapy of cancer cells.(3)The design of Au@Ag core-shell rodlike nanomatryoshka(RNMs),RNMs show strong SERS enhancement ability,and exhibit good tunability of SERS and photothermal properties.Contrast to common on-resonnace Raman probes,off-resonance probes exhibit lower photothermal damage and higher photostability.Off-resonance RNMs(Ag shell thickness,16.7 nm)exhibit best SERS performance and least photothermal effect,can effective reduce the photodamage to biosamples during SERS bioimaging process.However,on-resonance RNMs(1.8 nm)show better phototheraml capacity and moderate SERS enhancement,can be used for bioimaging and accompanied by photothermal therapy of cancer cells.Through systematic evaluation,three kinds of multifunctional nanoparticles show good application ability in bioimaging(such as two-photon fluorescence,SERS)and photothermal therapy of tumors.This work can well guide the design of new multifunctional nanoparticles.