Work

Light-Induced, Liquid Crystal-Templated Fabrication of Large-Area Pure Nanoporous Gold Films with High-Density Plasmonic Cavities

Year: 2024

Type: article

Abstract: Nanoporous gold (NPG) films are three-dimensional gold (Au) frameworks characterized by a uniform distribution of nanoscale irregular pores. Typically produced via a dealloying process, where the less noble silver (Ag) is selectively etched out, NPG films offer a large surface area, excellent chemical stability, remarkable catalytic activity, unique optical properties, and biocompatibility. These attributes make them invaluable for applications in catalysis, plasmonics, biosensors, and nanophotonics. However, the presence of residual Ag from the dealloying process can limit their performance in certain applications. In this study, we report a novel method for the fabrication of ultrapure, large-area NPG films (several cm 2 ) using a light-induced and liquid crystal-templated method. A hexagonal lyotropic liquid crystal containing a strong acid and a nonionic surfactant is combined with an aqueous solution of HAuCl 4, followed by the photochemical synthesis of gold nanoparticles (NPs) within the liquid crystal. After calcination of the Au NP-containing liquid crystal film at high temperature, pure NPG films are produced. We demonstrate surface-enhanced Raman spectroscopy (SERS) of Rhodamine 6G (R6G) molecules adsorbed on the NPG films and detect extremely low concentrations (below 10 –6 M) of R6G. Additionally, we thoroughly investigated the formation and optical properties of the NPG films. The results reveal that the ultrapure NPG films contain high-density plasmonic nanocavities, where substantial electromagnetic fields are generated, leading to significant enhancement of optical processes at nanoscale dimensions.

Source: The Journal of Physical Chemistry C

DOI: 10.1021/acs.jpcc.4c07053

Authors: Ozan Baran Orhan, Nahit Polat, Seren Demir, Fadime Mert Balci, Sinan Balci

Institution: Izmir Institute of Technology

Language: English

Topic: Gold and Silver Nanoparticles Synthesis and Applications

Subfield: Electronic, Optical and Magnetic Materials

Field: Materials Science

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $4,500

Funder: Türkiye Bilimsel ve Teknolojik Araştırma Kurumu