Zn2+-Induced Folding of RNA to Produce Honeycomb-like RNA-Mediated Fluorescing Zn2+/PbSe Nanostructures

This paper presents the synthesis of RNA-templated Zn2+/PbSe nanostructures following a colloidal approach. The nucleation and growth of PbSe on RNA matrix in the presence of Zn2+ and Pb2+ produces the porous Zn2+/PbSe building blocks through intramolecular folding, which in the process of self-assembly forms a honeycomb-like structure encapsulating Q-PbSe confined in the pores through intermolecular interactions. These nanostructures exhibit dual fluorescence in red and NIR regions at 806 nm (Phi(f) = 0.01) and 1050 nm (Phi(f) = 0.5), respectively. CD analysis reveals that Zn2+ induces the folding of RNA in the RNA-templated Zn2+/PbSe possibly involving the transformation from its B to A form. IR and NMR spectroscopy indicate an interaction of different components of RNA. An increase in the porosity with enhanced NIR absorption coefficient and fluorescence in the wavelength range of 900-1150 nm suggests the applications of these materials in the areas of sensing, biomedical, fluorescence imaging of tissues and for the incorporation dyes to enhance their light-harvesting capability.