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 (Φ_f = 0.01) and 1050 nm (Φ_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.