Plasmonic Sensing Characteristics of Gold Nanorods with Large Aspect Ratios
State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, Sun Yat-sen University, Guangzhou 510275, China
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Sensors 2018, 18(10), 3458; https://doi.org/10.3390/s18103458
Received: 18 September 2018
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Revised: 7 October 2018
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Accepted: 10 October 2018
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Published: 15 October 2018
(This article belongs to the Section Chemical Sensors)
Plasmonic gold nanorods play important roles in nowadays state-of-the-art plasmonic sensing techniques. Most of the previous studies and applications focused on gold nanorods with relatively small aspect ratios, where the plasmon wavelengths are smaller than 900 nm. Gold nanorods with large aspect ratios are predicted to exhibit high refractive-index sensitivity (Langmir 2008, 24, 5233–5237), which therefore should be promising for the development of high-performance plasmonic chemical- and bio-sensors. In this study, we developed gold nanorods with aspect ratios over 7.9, which exhibit plasmon resonances around 1064 nm. The refractive index (RI) sensitivity of these nanorods have been evaluated by varying their dielectric environment, whereby a sensitivity as high as 473 nm/RIU (refractive index unit) can be obtained. Furthermore, we have demonstrated the large-aspect-ratio nanorods as efficient substrate for surface enhanced Raman spectroscopy (SERS), where an enhancement factor (EF) as high as 9.47 × 108 was measured using 4-methylbenzenethiol (4-MBT) as probe molecule. Finally, a type of flexible SERS substrate is developed by conjugating the gold nanorods with the polystyrene (PS) polymer. The results obtained in our study can benefit the development of plasmonic sensing techniques utilized in the near-infrared spectral region.
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Keywords:
large aspect ratios; gold nanorods; refractive index sensitivities; SERS; plasmonic sensing
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MDPI and ACS Style
Zhuang, C.; Xu, Y.; Xu, N.; Wen, J.; Chen, H.; Deng, S. Plasmonic Sensing Characteristics of Gold Nanorods with Large Aspect Ratios. Sensors 2018, 18, 3458. https://doi.org/10.3390/s18103458
AMA Style
Zhuang C, Xu Y, Xu N, Wen J, Chen H, Deng S. Plasmonic Sensing Characteristics of Gold Nanorods with Large Aspect Ratios. Sensors. 2018; 18(10):3458. https://doi.org/10.3390/s18103458
Chicago/Turabian StyleZhuang, Chao, Yifan Xu, Ningsheng Xu, Jinxiu Wen, Huanjun Chen, and Shaozhi Deng. 2018. "Plasmonic Sensing Characteristics of Gold Nanorods with Large Aspect Ratios" Sensors 18, no. 10: 3458. https://doi.org/10.3390/s18103458
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