posted on 2008-03-13, 00:00authored byAnil Kumar, Vinit Kumar
RNA serves as an effective template for the synthesis of quantized CdS nanoparticles and mediates their
growth to create novel assemblies. Unlike DNA-stabilized particles in aqueous medium, these particles display
relatively strong emission at 2.34 eV, which is further enhanced by more than 2.5 fold and blue shifts to
higher energy (2.39 eV) upon aging. Chelation of Cd2+ with RNA restricts the nucleation of CdS. A variation
in the molar ratio of Cd/S from 2 to 6 produces different nanostructures with varied electronic properties.
Unlike general colloidal systems, aging of these nanoparticles produced smaller crystalline nanocrystals as
evidenced by their blue-shifted optical threshold and fluorescence maxima, and by atomic force microscopy
and transmission electron microscopy analysis. Different nanostructures grow upon aging to yield self-assembly
of different shapes, and the morphology and structure of these nanostructures could be manipulated by changing
the molar ratio of Cd/S. The formation of organized structures could provide a basis for controlled fabrication
of new nanostructures and nanodevices.