| Gold and gold nanoparticles have been widely used in various fields,such as in electronic sensor technology,nanotechnology,chemical and bio-medical technology,pharmaceutical technology and so on.This thesis designed and synthesized a series of 11-Mercaptoundecanoic acid(MUA)and Multi-functional polymer(LSA)coated gold nanoparticles;self assembly monolayers(SAMs)of ionic liquid were formed on gold surface,then the perfluoroalkyl anions assembled to the prepared gold surfaces via ion exchange.We have studied the effect of surface composition to protein adsorption and protein conformation.The surface properties,morphologies,structures and compositions of the functionalized materials were well characterized by X-ray photoelectron spectrometry(XPS),grazing incidence reflectance infrared spectroscopy(GIR),gontact angle(CA),transmission electron microscope(TEM),Fourier transform infrared spectroscopy(FTIR)and surface slasmon sesonance(SPR).1.The first part is a review about the relevant background of the work in this thesis including the preparation,development and application of functional gold surfaces and gold nanoparticles(AuNPs).2.We synthesized a series of MUA and LSA coated AuNPs of controlled and uniform size by the reduction with sodium citrate and sodium borohydride.The gold nanoparticles have desired properties such as good dispersibility and stability.By choosing sodium citrate and sodium borohydride,and adjusting the ratio of HAuC14 to the protecting agent,we obtained AuNPs with sizes of 10-75 nm and 1～6 nm,respectively.The properties of AuNPs were characterized by TEM,FTIR,UV visible spectrophotometer,dynamic light scattering(DLS)and so on.MUA coated AuNPs(FMUA-AuNPs)which has a diameter of 1.8 nm showed good fluorescent properties,having the maximum excitation wavelength at 325 nm and the maximum emission wavelength at 607 nm with the fluorescence quantum yield of 6.8%and Stock shift up to 282 nm.In addition,the stability of LSA coated AuNPs(LSA-AuNPs)were also studied,and we found that the LSA-AuNPs dispersion could be kept stable for more than 60 days in aqueous solution at room temperature and the dispersion could also be stably stored in 7.4 phosphate buffered solution(PBS)and Dulbecco Modified Eagle Medium(DMEM)solution over 3 days,which are ctitical to promise the applications in biomedicine.3.Self assembly monolayers of 1-mercapto-propyl-3-methylimidazolium bromide(MPMI-Br)were formed on gold surface,and subsequently the perfluoroalkyl anions were also assembled to the gold surfaces by ion exchange.The surface properties of these SAMs were characterized by XPS,GIR and CA,and their antifouling properties were also investigated by SPR.The used perfluoroalkyl anions including lithium bis(trifluoromethylsulfonyl)imide and sodium bis(perfluorobutylsulfonyl)imide.We found that temperature has little effect on the ion exchange;the exchange degree of ions in aqueous solution is higher than in acetonitrile;the contact angle of the functionalized gold surfaces was maximized with an ion exchange time up to 12 h.Theω-MPMI-PFOS/ω-MUD SAMs were also formed on gold surfaces via the modification of mixed MPMI-Br/11-mercapto-1-undecanol(MUD),and then followed by anionic exchange with perfluorooctane sulfonic acid potassium salt(PFOS).We had studied the effect of this functionalized SAMs on protein adsorption and protein conformation.The result shows that the 20%MPMI-PFOS SAM has highest resistance to protein adsorption;the adsorbed amount of fibrinogen(Fib)and bovine serum albumin(BSA)is 23 ng·cm-2,15 ng·cm-2 respectively.The biological activity of Fib protein was analyzed through GIR and Enzyme-Linked Immuno Sorbent Assay(ELISA)experiments.The result showed that the 20%MPMI-PFOS SAM maintains the best activity of Fib protein,possibly due to the synergistic action of F and O moities.We conclude that the surfaces,presenting the hydrophilic groups and hydrophobic groups at the same time,could resist protein adsorption and maintain protein favorable conformation. |
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