Developing probes for nucleic acids: a fluorescent furo-uridine nucleoside and acridine orange functionalized gold nanoparticles.

Probes for nucleic acids based on different modes of action have been prepared and studied. A modified fluorescent nucleoside bearing a furo-uridine nucleobase has been synthesized and preliminary photophysical measurements have been performed for the potential application as sensors based on fluorescent oligonucleotides. A second system constituted of water soluble acridine orange functionalized gold nanoparticles (ACR-AuNPs) has been obtained. A gold(III) salt has been chemically reduced in the presence of thiolic ligands able to form a protective monolayer on the gold surface: a mixture of thioalkylated tetraethylene glycol (TEG-SH) to confer the water solubility and a ligand synthesized on purpose (HALB), bearing an acridinium moiety at the non-binding extremity to give the DNA-sensitivity. Photophysics in the presence of DNA of the functionalized gold nanoparticles have been studied and potential applications have been investigated: nanodispersion into polyvinyl alcohol (PVA) thin films for mechanical stress responsive materials and cellular uptake for oligonucleotidic drug delivery