Synthesis of vinyl-terminated Au nanoprisms and nanooctahedra mediated by 3-butenoic acid: direct Au@pNIPAM fabrication with improved SERS capabilities. Issue 8 (29th January 2016)

• Record Type: Journal Article
• Authors: Casado-Rodriguez, M. A.; Sanchez-Molina, M.; Lucena-Serrano, A.; Lucena-Serrano, C.; Rodriguez-Gonzalez, B.; Algarra, M.; Diaz, A.; Valpuesta, M.; Lopez-Romero, J. M.; Perez-Juste, J.; Contreras-Caceres, R.
• Is Part Of: Nanoscale. Volume 8:Issue 8(2016)
• Page Start: 4557
• Page End: 4564
• Publication Date: 2016-01-29
• Subjects: Nanoscience -- Periodicals; Nanotechnology -- Periodicals; 620.505
• DOI: 10.1039/c5nr08054a
• Languages: English
• ISSNs: 2040-3364

Abstract

Abstract : A seedless synthesis of AuNTPs/AuNOC is described. Abstract : Here we describe the first seedless synthesis of vinyl-terminated Au nanotriangular prisms (AuNTPs) and nanooctahedra (AuNOC) in aqueous media. This synthesis is performed by chemical reduction of chloroauric acid (HAuCl4 ) with 3-butenoic acid (3BA) in the presence of benzyldimethylammonium chloride (BDAC). The principal novelties of the presented method are the use of a mixture of 3BA and BDAC, the synthesis of gold prisms and octahedra with controllable size, and the presence of terminal double bonds on the metal surface. Initially this method produces a mixture of triangular gold nanoprisms and octahedra; however, both morphologies are successfully separated by surfactant micelle induced depletion interaction, reaching percentages up to ∼90%. Moreover, the alkene moieties present on the gold surface are exploited for the fabrication of hybrid core@shell particles. Gold octahedra and triangular prisms are easily encapsulated by free radical polymerization of N -isopropylacrylamide (NIPAM). Finally, in order to obtain a gold core with the most number of tips, AuNTP@pNIPAM microgels were subjected to gold core overgrowth, thus resulting in star-shaped nanoparticles (AuSTs@pNIPAM). We use 4-amino-benzenethiol as the model analyte for SERS investigations. As expected, gold cores with tips and high curvature sites produced the highest plasmonic responses.