Urchin-like structures

Highly uniform y-Mn02 3D urchin-like and sisal-like nano-structures have been successfully prepared by a common hydrothermal method based on the reaction between MnS04 and KBr04. Reaction temperature and the addition of the polymer play an important role in influencing the methodologies of the as-obtained products [58]. 

In order to collect SERS spectra, nanoscaled structures are usually either fixed onto large surfaces or free in suspension in the form of nanoparticles. Suitable particles are available in a variety of forms simple spherical particles, rods, [13] rice-like shapes, [14] sea urchins [15], or even cages [16]. Their size can vary from 1 to 500 nm, and this factor has an important impact on their surface plasmon resonance properties. 

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