engleski

Adsorption mechanisms of RNA mononucleotides on silver nanoparticles

Surface-enhanced Raman scattering (SERS) of adenosine 5’-monophosphate (AMP), guanosine 5’-monophosphate (GMP), cytidine 5’-monophosphate (CMP) and uridine 5’-monophosphate (UMP) was obtained on a citrate-reduced silver colloid aggregated with sodium sulfate upon excitation with NIR radiation. Concentration dependent SERS spectra were dominated by vibrational bands of nucleic bases, revealing various adsorption mechanisms of RNA mononucleotides on the silver surface. For mononucleotides consisting of the purine bases, AMP and GMP, adsorption onto the silver nanoparticles through the larger six-membered ring was suggested, whereby two complexes with the silver surface were indicated for AMP, differing in involvement of the exocyclic amino group in bonding with the metal. The spectra of pyrimidine mononucleotides, CMP and UMP, implied position of the RNA building units with the carbonyl groups of the bases oriented towards the silver surface. Intense SERS bands observed in low wavenumber region supported chemical binding of all RNA mononucleotides with the silver nanoparticles.

RNA mononucleotides; Silver; Surface-enhanced Raman scattering

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