scholarly journals Hydroquinone-Based Fabrication of Gold Nanorods with a High Aspect Ratio and LSPR Greater than 850 nm to Be Used as a Surface Plasmon Resonance Platform for Rapid Detection of Thiophanate Methyl

2020 ◽  
Vol 10 (10) ◽  
pp. 3654
Author(s):  
Hang Nguyen Thi Nhat ◽  
Ngoc Thuy Trang Le ◽  
Nguyen Thi Phuong Phong ◽  
Dai Hai Nguyen ◽  
Minh-Tri Nguyen-Le

The use of gold nanorods (AuNRs) as surface-enhanced Raman scattering (SERS) substrates has gained much attraction due to their remarkably aspect-ratio-dependent plasmonic properties. In this report, we described the development of AuNRs with a high aspect ratio and longitudinal surface plasmon resonance (LSPR) >850 nm through a hydroquinone-based fabrication with minor modifications. The synthesis started with the reduction of chloroauric acid (HAuCl4) by sodium borohydride (NaBH4) to make gold nanoseeds from which AuNRs were grown with the aid of silver nitrate (AgNO3), HAuCl4, cetyltrimethylammonium bromide (CTAB), and hydroquinone (HQ). Scanning electron microscopy coupled with energy-dispersive X-ray (SEM-EDX), Transmission electron microscope (TEM), X-ray diffraction (XRD) and Ultra-violet-Visible spectroscopy (UV-Vis) were performed to study the shape, size, and structural and optical properties of AuNRs, respectively. The results showed that AuNRs with high aspect ratios (AR > 3) were single crystals with a heterogenous size distribution, and that the growth of Au nanoseeds into AuNRs took place along the [001] direction. AuNRs exhibited two plasmon resonance peaks at 520 nm and 903 nm, while gold nanoseeds had only a plasmon resonance peak at 521 nm. The as-synthesized AuNRs also showed SERS effects for thiophanate methyl, a broad-spectrum fungicide, with the limit of detection down to 5 mg/L of the fungicide. AuNR-coated glass can serve as a SERS-based sensing platform for rapid detection of thiophanate methyl with high sensitivity and reproducibility.

2014 ◽  
Vol 602-603 ◽  
pp. 993-997
Author(s):  
Gui Jun Ban ◽  
Xiu Li Fu ◽  
Zhi Jian Peng

Gold nanorods with different aspect ratios, exhibiting localized surface plasmon resonance in a tuned longitudinal mode, were prepared by employing a seed mediated growth approach. Their third-order nonlinear optical properties were investigated by using femtosecond Z-scan technique at 800 nm. All the prepared gold nanorods with different aspect ratios exhibited a reverse saturation absorbance behavior, and the value of effective nonlinear absorption coefficient reaches its maximum when the longitudinal surface plasmon resonance peak of the gold nanorods located near the excitation wavelength.


Author(s):  
Thi Nhat Hang Nguyen ◽  
Thi Le Trinh Nguyen ◽  
Thi Thanh Tuyen Luong ◽  
Canh Minh Thang Nguyen ◽  
Thi Phuong Phong Nguyen

2014 ◽  
Vol 16 (5) ◽  
pp. 1820-1823 ◽  
Author(s):  
Xóchitl López-Lozano ◽  
Hector Barron ◽  
Christine Mottet ◽  
Hans-Christian Weissker

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1728
Author(s):  
Joshua Fernandes ◽  
Sangmo Kang

The near-field enhancement and localized surface plasmon resonance (LSPR) on the core-shell noble metal nanostructure surfaces are widely studied for various biomedical applications. However, the study of the optical properties of new plasmonic non-spherical nanostructures is less explored. This numerical study quantifies the optical properties of spherical and non-spherical (prolate and oblate) dimer nanostructures by introducing finite element modelling in COMSOL Multiphysics. The surface plasmon resonance peaks of gold nanostructures should be understood and controlled for use in biological applications such as photothermal therapy and drug delivery. In this study, we find that non-spherical prolate and oblate gold dimers give excellent tunability in a wide range of biological windows. The electromagnetic field enhancement and surface plasmon resonance peak can be tuned by varying the aspect ratio of non-spherical nanostructures, the refractive index of the surrounding medium, shell thickness, and the distance of separation between nanostructures. The absorption spectra exhibit considerably greater dependency on the aspect ratio and refractive index than the shell thickness and separation distance. These results may be essential for applying the spherical and non-spherical nanostructures to various absorption-based applications.


2011 ◽  
Vol 22 (26) ◽  
pp. 265705 ◽  
Author(s):  
S L Smitha ◽  
K G Gopchandran ◽  
T R Ravindran ◽  
V S Prasad

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