Nanochemistry and biotechnology
The Spectral Properties Peculiarities of DNA-Ag ions system
Gryn D.V.1, Yashchuk V.M.1
1 Taras Shevchenko National University of Kyiv, Physics faculty,
Volodymyrs’ka str. 64/13, Kyiv, 01601, Ukraine. 
E-mail: dm_gryn@ukr.net

DNA is vitally important macromolecule and often used in various fields of biochemistry, biology and medicine.
In many experiments the DNA fluo- and phosphorescence emission is observed and investigated. 
It is well known the property of Ag+ ions to accumulating on the DNA, from sepatate ions in solution to some small nano-clusters near DNA, and then to clusters and nanoparticles. This is often used in controlled nanoparticles grows on DNA used as a template.
In this work we analyze the influence of presence of Ag+ ions on the DNA spectral properties.
Water solutions of DNA, and DNA-Ag samples of different DNA:Ag ratios were investigated at room and nitrogen (77K) temperatures.
The UV-vis spectra as well as fluorescence and phosphorescence spectra of DNA in presence of different quantity of Ag were compared to pure DNA spectra.
It is shown that Ag ions do not affect essentially on the DNA absorption. Presence of AgNO3 in DNA water solution leads to sharp phosphorescence intensity increasing (more that 500x times at 77 K), compared to fluorescence, and also additional structure in phosphorescence spectra appears. This structure has been identified as adenine base phosphorescence.

1.	Grebinyk, A., Yashchuk, V., Bashmakova, N. et al. A new triple system DNA-Nanosilver-Berberine for cancer therapy // Applied Nanoscience.-2019.-9,.-P. 945–956.
2.	Dmytro V. Gryn, Valeriy M. Yashchuk & Zenovii Yu. Tkachuk (2021) Some peculiarities of spectral properties of various compounds of adenine nucleotide and polynucleotide //  Molecular Crystals and Liquid Crystals, 717:1, 54-59.