The Construction And Application Of Functionalized Gold Nanoparticle Monolayer Film

The construction of functionalized gold nanoparticle monolayers is of great value and significance for the further application and research of precious metal nanomaterials in various research fields.The physicochemical properties of noble metal nanomaterials are generally predetermined by the composition,structure,size,and assembly morphology of the particles themselves.Therefore,it is possible to prepare a large-area functionalized nanoparticle monolayer film using a simple and effective water-oil interface self-assembly method,via introducing a smart-responsive polymer to modify nanoparticles and designing gold nanoparticles with specific structures.And it can be used in research fields such as optoelectronic devices,bio-detection,security anti-counterfeiting and surface enhanced Raman scattering(SERS).In this paper,gold nanoparticles(Au NPs)were modified by oligoethylene glycol(OEG)-based dendronized copolymer(PG1A)with temperature and pH response properties,which were used for constructing the gold nanoparticle monolayer film with a dual response properties and its surface plasmon resonance(SPR)signal can be reversibly adjusted;using glutathione molecules with chiral properties to induce the growth of gold nanorod particles(Au NRs),the gold nanorod particles with multi-spike structure(MS-Au NRs)were prepared,which possess chiral optical properties and SPR located in the near infrared region.Moreover,the nanoparticle monolayer with chiral property was formed by MS-Au NRs self-assembly at the water-oil interface;the multi-concave structure of gold nanoparticles(MC-Au NPs)was designed to self-assemble at the water-oil interface for forming a monolayer film,which was used to construct a kind of SERS sensor with sandwich structure based on flexible patterned substrate.In view of the excellent properties of functionalized gold nanoparticle monolayers,which offers more possibilities for various applications such as security anti-counterfeiting labels and surface-enhanced Raman scattering.Based on the construction and functionalization of gold nanoparticle monolayers,this paper is mainly carried out from the following three works:1)The Au NPs was modified with temperature and pH responsive PG1 A,and self-assembling at the water-oil interface to form a large-area and free-standing nanoparticle monolayer film.While the ambient temperature and pH were changed,the local surface plasmon resonance(LSPR)property of gold nanoparticle films,as well as their excellent physical and mechanical properties,easy transfer property and inherent color were investigated.And using these excellent performances of the monolayer film,the security anti-counterfeiting label was carried out for further application.2)By means of seed-induced growth method,the MS-Au NRs with Au NRs as seeds were synthesized in the presence of L-reduced glutathione molecules(L-GSH),which possess chiral optical properties and SPR in near-infrared region.In addition,the spike structure with growth site,size and number of MS-Au NRs,as well as the physical optical properties were studied during the content change of L-GSH molecules and Au NRs seeds.And the large-area nanoparticle monolayer film was prepared by MS-Au NRs assembling at water-oil interface.3)A flexible patterned polydimethylsiloxane(P-PDMS)based sandwich SERS sensor was fabricated self-assembled large-area monolayer film with MC-Au NPs.The design of nanoparticles with multi-concave structure,patterned flexible substrate and sandwich structure in this system were investigated on the Raman signal amplification of the SERS sensor.