Related Experiment Video
Updated: Sep 22, 2025
Development of an Electrochemical DNA Biosensor to Detect a Foodborne Pathogen
Published on: June 3, 2018
Electrochemical investigation of DNA-metal complex interactions and development of a highly sensitive electrochemical
Majid Arvand1, Hoda Ilkhani2, Mohamad Reza Ganjali3
1Electroanalytical Chemistry Laboratory, Faculty of Chemistry, University of Guilan, Namjoo Street, P.O. Box: 1914-41335, Rasht, Iran.
Abstract:
Metal ion-DNA interactions are important in nature as they often change the genetic material's structure and function. In this work, new Tb complex of TbCl3 (tris(8-hydroxyquinoline-5-sulfonic acid) terbium) (Tb(QS)3) was used as an electrochemical indicator for investigation of DNA-metal interaction and then a new DNA biosensor was designed using this complex. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used to study the interaction of Tb(QS)3 with double-stranded DNA (ds-DNA). It was found that Tb(QS)3 presented an excellent electrochemical activity on carbon paste electrode (CPE) and could intercalate into the double helix of double-stranded DNA. The interaction mechanism was elucidated in DNA solution and DNA modified carbon paste electrode by using differential pulse voltammetry and cyclic voltammetry. The binding ratio between this complex and ds-DNA was calculated to be 1:1. The extent of hybridization was evaluated on the basis of the difference between signals of Tb(QS)3 with probe DNA before and after hybridization with complementary DNA. With this approach, target DNA could be detected in the range from 0.03 to 0.185 μM with detection limit of 0.021 μM. The interaction mode between Tb(QS)3 and DNA was found to be mainly intercalative interaction.
