Direct formation of gold nanorods on surfaces using polymer-immobilised gold seeds

Abstract

SummaryHerein, we present the formation of gold nanorods (GNRs) on novel gold–poly(methyl methacrylate) (Au–PMMA) nanocomposite substrates with unprecedented growth control through the polymer molecular weight (M w) and gold-salt-to-polymer weight ratio. For the first time, GNRs have been produced by seed-mediated direct growth on surfaces that were pre-coated with polymer-immobilised gold seeds. A Au–PMMA nanocomposite formed by UV photoreduction has been used as the gold seed. The influence of polymer M w and gold concentration on the formation of GNRs has been investigated and discussed. The polymer nanocomposite formed with a lower M w PMMA and 20 wt % gold salt provides a suitable medium for growing well-dispersed GNRs. In this sample, the average dimension of produced GNRs is 200 nm in length with aspect ratios up to 10 and a distribution of GNRs to nanoparticles of nearly 22%. Suitable characterization techniques such as AFM and SEM have been used to support concept of the proposed growth method.

A Sub-Microanalysis Approach in Chemical Characterisation of Gold Nanorods Formed by a Novel Polymer-Immobilised Gold Seeds Base

“…In an absorption image, any changes in grey scale can be caused by changes in topographic morphology of the sample. The absorption image is in compliance with the scanning electron microscope (SEM) and atomic force microscope (AFM) images taken on UV irradiated PMMA and reported in our previous publications [ 17 , 25 ]. Figure 1 a represents surface roughening that is depicted as a result in variation of mechanical and chemical properties of polymer due to main chain scission [ 26 , 27 ].…”

“…Protruded gold nanoparticles formed over the PMMA matrix provide a well-dispersed seed platform for the growth of GNRs. Figure 1 shows evolution of GNRs formation using a polymer-immobilised gold seeds method proposed recently for the first time by the author [ 17 ]. Figure 1 a shows an X-ray absorption image in transmission scale (SXM image taken at E hν = 550 eV) of low molecular weight ( M w) PMMA (P1) spin casted onto a silicon nitride membrane and irradiated by UV light (assigned as P1-UV) resulting in a speckle pattern.…”

“…Figure 1 c demonstrates how GNRs have been formed over surface of Au–PMMA nanocomposite with 60 wt % (assigned as P2-60-GNRs) using a novel polymer-immobilised gold seeds mediated method [ 17 ]. Figure 1 d is a magnified image of the region in Figure 1 c demarcated with a red squared frame.…”

“…In this fast-growing science and technology field, there are always high demands for new and novel approaches to produce and fabricate one-dimensional nanomaterials that will definitely be of great interest to scientists and engineers, especially if the synthesis procedure is simpler and can be adopted with various surfaces and be used over extended areas and volumes. Recently, we proposed a proof of concept for formation of GNRs by a novel polymer-immobilised seed mediated method reported in reference [ 17 ]. For the first time, gold nanoparticles immobilised within PMMA polymer matrix were applied as seeds on which nanorods (NRs) grow using a seed-mediated method.…”

Noble Metal Nanostructured Materials for Chemical and Biosensing Systems

“…Majid's group present the formation of AuNRs on novel Au-poly(methyl methacrylate) nanocomposite substrates, which is formed by ultraviolet (UV) photoreduction. [64].…”