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nanotechweb.org - Ring-like assembly of Gold nanoparticles for enhanced SERS detection

DCN Corp® - Overview: (a). and magnified, and (b) SEM images of 282 nm Silica colloidal crystals decorated with 25 nm Gold nanoparticles (AuNP)Self-assembled Gold nanoparticles (AuNP) can be used as an effective and low-cost substrate for Surface-Enhanced Raman Scattering (SERS) ultra-detection.  The simple clustering of colloidal Gold (Au) allows the enhancement of the Raman signal up to 10-10 in nanoscale gaps between the particles.  However, the synthesis of well ordered and reproducible nanoparticle arrays at a large scale still remains a challenge.  Confirming the results in Nanotechnology [1] - researchers have investigated a simple and versatile dip drawing technique to achieve this

A multi-disciplinary team have managed to develop a novel method for producing high quaity Silica colloidal crystals (CCs) at the centimetre scale.  The team includes researchers from the Institute of Biochemistry and Physiology of Plants and Micro-organisms and the Institute of Laser and Information Technologies, Saratov State University, Russia.  They worked collaboratively with the School of Engineering and Materials Science, Queen Mary University of London (QM UoL), UK.

The highest quality two dimensional (2D) CCs were obtained with aqueous monodisperse Silica colloids at room temperature and with a time of several minutes.  The decoration of CCs with AuNP and nanorods results in the formation of ring-like chains.  These have a preferential tail-to-tail orientation along the hexagonal boundaries.  Such nanoparticle packaging leads to a strong field enhancement in the nanoscale gaps between the nanoparticles.

Owing to the unique packaging, the nanostructures demonstrate an analytical SERS enhancement factor of at least 10 times higher then that for a random nanoparticle assembly.  Such an advantage, together with the highly reproducible SERS response, provides a commercial opportunity to employ such materials for quantitative SERS analytics. Original article available here

Interestingly the research, above, continues to highlight the unique potential of nanoparticles.  As stated previously, DCN Corp strongly believes it can contribute, by increasing the SERS magnitude. Going forward, if you and/or your colleagues are interested in making DCN Corp's alternative process reality - please ensure to contact the company as soon as practicably possible.

[1] Khanadeev, V. A., Khlebtsovl, B. N., Klimova, S. A., Tsvetkov, M. Y., Bagratashvili, V. N., Sukhorukov, G. B. and Khlebtsovl, N. G. Large-scale high-quality 2D silica crystals: dip-drawing formation and decoration with gold nanorods and nanospheres for SERS analysis. Nanotechnology 25, 40 (2014) Journal citation available here