Electron irradiation-assisted fabrication of gold nanoparticle films and their applications to highly sensitive detection of hazardous materials

Abstract

Metal nanoparticles (NPs) can play an important role in the field of nanotechnology and environmental technology due to its unique physical and chemical characteristics. In particular, NPs of noble metal such as gold (Au), silver, copper are applicable to optics, detection of biochemical materials, catalysts, surface-enhanced Raman scattering (SERS) since they have excellent optical, electronic, and catalytic properties. In addition, noble metal NPs with Platonic shapes such as tetrahedron, cube, octahedron, decahedron, icosahedrons have sharp corners and edges, thereby strong enhancement of local electromagnetic field is possible. Thus they can have a significant impact on the surface-enhanced spectroscopy, chemical and biological sensors, and nano-device development. Furthermore, patterning or controlled assembly of noble metal NPs is highly important for biological sensors, micro/nano-electrical devices, optical and photovoltaic devices, and SERS-active substrates. Among the wide variety of applications, SERS is a powerful tool for the detection of minute amount of biochemical or radioactive materials adsorbed on noble metal NPs. The Raman scattering intensity of biochemical or radioactive materials tends to be maximized on the nanostructured metal surfaces, which is due to the enhanced elec-tromagnetic field by localized surface plasmon resonance (LSPR). In this study, Au NP films were fabricated by electron irradiation and thermal treatment of Au precur-sor materials. The shape and size of Au NPs were controlled by adjusting the composition, thickness, and con-centration of the precursor materials, and through which spherical and octahedral Au NP films could be suc-cessfully fabricated. The Au NP films with pure surfaces could also be fabricated by post-cleaning process and showed unique optical properties in accordance with particle shape and sizes. In addition, patterned spherical and octahedral Au NP films were fabricated. Due to the cross-linking beha...