title: Hierarchical organization and molecular diffusion in gold nanorod/silica supercrystal nanocomposites.
abstract: Hierarchical organization of gold nanorods was previously obtained on a substrate, allowing precise control over the morphology of the assemblies and macroscale spatial arrangement. Herein, a thorough description of these gold nanorod assemblies and their orientation within supercrystals is presented together with a sol-gel technique to protect the supercrystals with mesoporous silica films. The internal organization of the nanorods in the supercrystals was characterized by combining focused ion beam ablation and scanning electron microscopy. A mesoporous silica layer is grown both over the supercrystals and between the individual lamellae of gold nanorods inside the structure. This not only prevented the detachment of the supercrystal from the substrate in water, but also allowed small molecule analytes to infiltrate the structure. These nanocomposite substrates show superior Raman enhancement in comparison with gold supercrystals without silica owing to improved accessibility of the plasmonic hot spots to analytes. The patterned supercrystal arrays with enhanced optical and mechanical properties obtained in this work show potential for the practical implementation of nanostructured devices in spatially resolved ultradetection of biomarkers and other analytes.
authors.affiliation: Bionanoplasmonics Laboratory, CIC biomaGUNE, Paseo de Miramón 182, 20009 Donostia - San Sebastian, Spain. llizmarzan@cicbiomagune.es.
authors.forename: Cyrille
authors.initials: C
authors.lastname: Hamon
authors.affiliation: Bionanoplasmonics Laboratory, CIC biomaGUNE, Paseo de Miramón 182, 20009 Donostia - San Sebastian, Spain. llizmarzan@cicbiomagune.es.
authors.forename: Marta N
authors.initials: MN
authors.lastname: Sanz-Ortiz
authors.affiliation: Electron Microscopy and Image Processing Interdisciplinary Laboratory, Far Eastern Federal University, Sukhanova 8, 690000, Vladivostok, Russia and Electron Microscopy Laboratory, CIC NanoGUNE Consolider, Tolosa Hiribidea, 76, 20019 Donostia - San Sebastian, Spain.
authors.forename: Evgeny
authors.initials: E
authors.lastname: Modin
authors.affiliation: Bionanoplasmonics Laboratory, CIC biomaGUNE, Paseo de Miramón 182, 20009 Donostia - San Sebastian, Spain. llizmarzan@cicbiomagune.es.
authors.forename: Eric H
authors.initials: EH
authors.lastname: Hill
authors.affiliation: Bionanoplasmonics Laboratory, CIC biomaGUNE, Paseo de Miramón 182, 20009 Donostia - San Sebastian, Spain. llizmarzan@cicbiomagune.es.
authors.forename: Leonardo
authors.initials: L
authors.lastname: Scarabelli
authors.affiliation: Electron Microscopy Laboratory, CIC NanoGUNE Consolider, Tolosa Hiribidea, 76, 20019 Donostia - San Sebastian, Spain and Basque Foundation of Science, IKERBASQUE, 48013 Bilbao, Spain.
authors.forename: Andrey
authors.initials: A
authors.lastname: Chuvilin
authors.affiliation: Bionanoplasmonics Laboratory, CIC biomaGUNE, Paseo de Miramón 182, 20009 Donostia - San Sebastian, Spain. llizmarzan@cicbiomagune.es and Basque Foundation of Science, IKERBASQUE, 48013 Bilbao, Spain and Biomedical Research Networking Center in Bioengineering, Biomaterials, and Nanomedicine, CIBER-BBN, Spain.
authors.forename: Luis M
authors.initials: LM
authors.lastname: Liz-Marzán