title: Highly controlled silica coating of PEG-capped metal nanoparticles and preparation of SERS-encoded particles.
abstract: Thiol-modified poly(ethylene glycol) (mPEG-SH) has been used to replace standard capping agents from the surfaces of gold nanoparticles with different sizes and shapes. Upon PEG stabilization, the nanoparticles can be transferred into ethanol, where silica can be directly grown on the particle surfaces through the standard Stober process. The obtained silica shells are uniform and homogeneous, and the method allows a high degree of control over shell thickness for any particle size and shape. Additionally, Raman-active molecules can be readily incorporated within the composite nanoparticles during silica growth so that SERS/SERRS-encoded nanoparticles can be fabricated containing a variety of tags, thereby envisaging multiplexing capability.
authors: Departamento de Química Física and Unidad Asociada CSIC-Universidade de Vigo, 36310 Vigo, Spain.
authors: Cristina
authors: C
authors: Fernández-López
authors: Cintia
authors: C
authors: Mateo-Mateo
authors: Ramón A
authors: RA
authors: Alvarez-Puebla
authors: Jorge
authors: J
authors: Pérez-Juste
authors: Isabel
authors: I
authors: Pastoriza-Santos
authors: Luis M
authors: LM
authors: Liz-Marzán
mesh_terms: D020099:Coated Materials, Biocompatible / Q000138:chemical synthesis*; D000431:Ethanol; D053768:Metal Nanoparticles / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*; D013059:Spectrum Analysis, Raman / Q000379:methods*; D013438:Sulfhydryl Compounds
chemical_list: D020099:Coated Materials, Biocompatible; D013438:Sulfhydryl Compounds; D000431:Ethanol; D011092:Polyethylene Glycols; D012822:Silicon Dioxide