Surface interactions of gold nanorods and polysaccharides: From clusters to individual nanoparticles

• Published in: Carbohydrate polymers 2016-11, Vol.152, p.479-486
• Main Authors: de Barros, Heloise Ribeiro, Piovan, Leandro, Sassaki, Guilherme L., de Araujo Sabry, Diego, Mattoso, Ney, Nunes, Ábner Magalhães, Meneghetti, Mario R., Riegel-Vidotti, Izabel C.
• Format: Article
• Language: English
• Subjects: Gold nanorods; Self-assembling; Sulfated chitosan; Surface interactions
• ISSN: 0144-8617; 1879-1344
• DOI: 10.1016/j.carbpol.2016.07.018

[Display omitted] •Sulfated chitosan efficiently interact with the surface of CTAB coated AuNRs.•Sulfated chitosan produced well-dispersed individually wrapped CTAB/AuNRs.•Gum arabic produced clusters of CTAB-coated AuNRs.•The CTAB/AuNRs/polysaccharide interactions were investigated through FTIR. Gold nanorods (AuNRs) are suitable for constructing self-assembled structures for the development of biosensing devices and are usually obtained in the presence of cetyltrimethylammonium bromide (CTAB). Here, a sulfated chitosan (ChiS) and gum arabic (GA) were employed to encapsulate CTAB/AuNRs with the purpose of studying the interactions of the polysaccharides with CTAB, which is cytotoxic and is responsible for the instability of nanoparticles in buffer solutions. The presence of a variety of functional groups such as the sulfate groups in ChiS and the carboxylic groups in GA, led to efficient interactions with CTAB/AuNRs as evidenced through UV–vis and FTIR spectroscopies. Electron microscopies (HR-SEM and TEM) revealed that nanoparticle clusters were formed in the GA-AuNRs sample, whereas individual AuNRs, surrounded by a dense layer of polysaccharides, were observed in the ChiS-AuNRs sample. Therefore, the presented work contributes to the understanding of the driving forces that control the surface interactions of the studied materials, providing useful information in the building-up of gold self-assembled nanostructures.