The effect of pH on the interaction between Eu3+ ions and short single-stranded DNA sequence, studied with electrochemical, spectroscopic and computational methods

• DOI: 10.1016/j.msec.2012.01.002
• Publication Date: 2012-01-12T21:10:25Z
• Authors: Hoda Ilkhani; Mohammad Reza Gan...; Majid Arvand; Farnoush Faridbod; Parviz Norouzi
• Keywords: Differential pulse voltammetry; Sequence (biology)

Abstract For the first time, interaction of short single-stranded DNA (ssDNA) sequence with Eu 3 + was studied by cyclic voltammetry (CV), differential pulse voltammetry (DPV) and UV–vis spectroscopy. The results show that interaction between Eu 3 + ions and ssDNA is related to solution pH and pK a of ssDNA bases and have different binding mode at different pHs. It's clear that, at pH 3.7, only phosphate groups of ssDNA can interact with Eu 3 + ions, because in this pH ssDNA bases are totally protonated. But at higher pH (5.5), some of ssDNA bases can interact with Eu 3 + ions, too. Computational studies were done and confirm the result of experimental data. The agreement mutually verifies the accuracy of the methods.