One-step wet chemical synthesis of gold nanoplates on solid substrate using poly-l-lysine as a reducing agent

Suratun Nafisah; Marlia Morsin; Nur Anida Jumadi; Nafarizal Nayan; Nur Zehan An'nisa Md Shah; Nur Liyana Razali; Muhammad Mat Salleh

doi:10.1016/j.mex.2018.12.002

One-step wet chemical synthesis of gold nanoplates on solid substrate using poly-l-lysine as a reducing agent

MethodsX. 2018 Dec 4:5:1618-1625. doi: 10.1016/j.mex.2018.12.002. eCollection 2018.

Authors

Suratun Nafisah^{1

2}, Marlia Morsin^{1

2}, Nur Anida Jumadi^{1

2}, Nafarizal Nayan^{1

2}, Nur Zehan An'nisa Md Shah^{1

2}, Nur Liyana Razali^{1

2}, Muhammad Mat Salleh³

Affiliations

¹ Microelectronics & Nanotechnology - Shamsuddin Research Centre (MiNT-SRC), Institute of Integrated Engineering, Universiti Tun Hussein Onn Malaysia, 86400, Parit Raja, Batu Pahat Johor, Malaysia.
² Department of Electronics, Faculty of Electrical and Electronic Engineering, Universiti Tun Hussein Onn Malaysia, 86400, Parit Raja, Batu Pahat Johor, Malaysia.
³ Institute of Microengineering and Nanoelectronics (IMEN), Universiti Kebangsaan Malaysia, 43600, Bangi, Selangor, Malaysia.

Abstract

A one-step wet chemical approach or seedless growth process has several advantages compared to the traditional seed-mediated growth method (SMGM), such as being simpler and not requiring a multistep growth of seeds. This study had introduced a one-step wet chemical method to synthesis gold nanoplates on a solid substrate. The synthesis was carried out by simply immersing clean ITO substrate into a solution, which was made from mixing of gold chloride (precursor), cetyltrimethylammonium bromide or CTAB (stabilizing agent), and poly-l-lysine or PLL (reducing agent). Consequently, the size of the nanoplates in the range of (0.40 - 0.89) μm and a surface density within the range (21.89-57.19) % can be easily controlled by changing the concentration of PLL from 0.050 to 0.100 w/v % in H₂O. At low PLL concentrations, the reduction of the gold precursor by PLL is limited, leading to the formation of gold nanoplates with a smaller size and surface density. The study on the sample by using energy-dispersive x-ray spectroscopy (EDS) confirmed that gold peaks occurred. The optical properties of the samples were examined by a UV-vis Spectrophotometer and showed that there was no strong surface plasmon resonance band observed at UV-vis and infrared regions, which agreed to micron-sized gold nanoplates. •Gold nanoplates synthesized on the substrate using a simple one-step wet chemical synthesis approach with poly-l-lysine (PLL) as a reducing agent and CTAB as a stabilizing agent.•The nanoplate's size and surface density was strongly dependent on the concentration of PLL.•Gold nanoplates synthesized using PLL with a concentration 0.050% showed perfect triangular shape, less by-products and more homogenous in size.

Keywords: Gold nanoparticles; Gold nanoplates; Localized surface plasmon resonance; One-step wet chemical synthesis of Gold Nanoplates on Solid Substrate Using Poly-l-lysine as Reducing Agent; Plasmonic sensor.