Nano Archive

Size and shape control in the overgrowth of gold nanorods

Ratto, Fulvio and Matteini, Paolo and Rossi, Francesca and Pini, Roberto (2010) Size and shape control in the overgrowth of gold nanorods. Journal of Nanoparticle Research, 12 (6). pp. 2029-2036.

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We report on a new sustainable approach to manipulate the optical behaviour and geometrical properties of gold nanorods in aqueous solutions by fine control of their overgrowth. In our approach, the overgrowth is realized by modulation of the reduction of the gold ions which are left as Au1+ after the primary step of the synthesis (typically as much as ~80% of the gold ions available in the growth solution). The progress of the reduction requires the gradual addition of ascorbic acid, which transforms the Au1+ into Au0 and may be performed in the original growth solution with no need for any further manipulation. By control of the total amount and rate of administration of the ascorbic acid, we prove the possibility to realize a systematic modulation of the average lengths, diameters, shapes (rod or dog-bone like), and light extinction of the nanoparticles. A slow overgrowth leads to a gradual enlargement of the lengths and diameters at almost constant shape. In contrast, a faster overgrowth results into a more complex modification of the overall shape of the gold nanorods.

Item Type:Article
Uncontrolled Keywords:Metal colloids - Gold nanorods - Light absorption - Rayleigh scattering - Nanoparticle synthesis
Subjects:Material Science > Nanofabrication processes and tools
ID Code:9467
Deposited By:SPI
Deposited On:02 Aug 2010 17:44
Last Modified:02 Aug 2010 17:44

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