engleski

Binding of a new phosphonium dye with AT polynucleotide studied by SERS

Surface-enhanced Raman scattering (SERS) of a new phosphonium dye was studied on a citrate-reduced silver colloid upon NIR excitation. Differences in relative band intensities between spectra were attributed to concentration dependent variations in position of the dye molecules on the silver surface, whereby at high concentration intermolecular stacking was suggested. Known for its ability to interact with DNA, SERS spectra of the dye with alternating adenine-thymine polynucleotide were acquired. Although all studied dye/poly dAdT-poly dAdT mixtures contained the same amount of the dye, at excess of polynucleotide the spectrum of the complex resembled the spectrum of the dye at low concentration, while excess of the dye over biopolymer produced the spectrum similar to that at high dye concentration. Given that excess of the dye induces formation of dimer while binding with AT polynucleotide, observed spectra could be indicative of the dye assembly within the polynucleotide groove.

surface-enhanced Raman scattering; phosphonium dye; polynucleotide

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