title: Surface-enhanced Raman spectroscopy (SERS) for sub-micromolar detection of DNA/RNA mononucleotides.
abstract: Surface-enhanced Raman (SER) spectra of all the DNA/RNA mononucleotides have been obtained with high sensitivity using citrate-reduced silver colloids aggregated with MgSO4, rather than the more usual halide ions, which were found to prevent enhancement of these compounds. The SERS spectra of adenine, guanine, thymine, cytosine, and uracil were recorded along with their corresponding nucleosides and 5'-deoxynucleotides. For the cytosine series, all three spectra had similar relative band intensities but the spectra of adenine were different from those of adenosine and dAMP, probably due to differences in orientation on the surface. No enhanced bands from the phosphate or sugar groups were observed. There were general similarities between the SERS spectra of the purine mononucleotides and the pyrimidine mononucleotides, but the spectra were sufficiently different to allow each of them to be distinguished. This method can therefore be used for high sensitivity, label-free identification of mononucleotides.
authors.affiliation: Innovative Molecular Materials Group, School of Chemistry & Chemical Engineering, Queen's University, Belfast BT9 5AG, Northern Ireland. s.bell@qub.ac.uk
authors.forename: Steven E J
authors.initials: SE
authors.lastname: Bell
authors.forename: Narayana M S
authors.initials: NM
authors.lastname: Sirimuthu
mesh_terms: D015374:Biosensing Techniques; D004247:DNA / Q000032:analysis* / Q000737:chemistry; D011687:Purines / Q000032:analysis / Q000737:chemistry; D011743:Pyrimidines / Q000032:analysis / Q000737:chemistry; D012313:RNA / Q000032:analysis* / Q000737:chemistry; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013059:Spectrum Analysis, Raman / Q000295:instrumentation / Q000379:methods*
chemical_list: D011687:Purines; D011743:Pyrimidines; D012313:RNA; D004247:DNA; C030986:pyrimidine; C030985:purine