Application of mercury-mediated thymine-base pairs for successful voltammetric detection of HPV 18

Formation of mercury(II)-mediated thymine base pairs (T - Hg(II) - T) can be successfully used for efficiently bonding partially complementary, thymine rich DNA sequences. For the first time this highly selective T - Hg(II) - T connection was used for effective voltammetric detection of specific DNA sequences characteristic for Human Papillomavirus type 18 (HPV 18) without additional labeling step. The detection of target DNA sequence was based on the electrochemical reduction signal of Hg(II) ions bonded with opposite thymine bases (mispairs) in DNA helix. The obtained detection and quantification limits were equaled (1.2 +/- 0.2).10(-14) and (7.5 +/- 0.1).10(-14) M respectively. Furthermore the laser ablation coupled with inductively coupled plasma mass spectrometry (LA-ICP-MS) and circular dichroism (CD) were used as an auxiliary technique to get additional information and confirm the formation of DNA duplex via specific interaction between Hg(II) ions and thymine bases. (C) 2016 Elsevier B.V. All rights reserved.