A modification free hybridization biosensor for detection of DNA sequence based on Zr(IV) ion glue mediated the adsorption on Au-MPA SAM electrode

作者：Shervedani Reza Karimi^*; Pourbeyram Sima

来源：Sensors and Actuators B: Chemical , 2011, 160(1): 145-153.

DOI：10.1016/j.snb.2011.07.025

• DNA
• Hybridization
• Mismatch
• Zirconium ion
• Electrochemical impedance spectroscopy

A simple method is developed for electrochemical detection of DNA sequence. The probe DNA (p-DNA) is immobilized onto Au-MPA SAM electrode modified with zirconium ion, Zr(IV). The electrochemical results imply that immobilization is performed effectively via the phosphate groups with no implication of the p-DNA bases in the immobilization stage, ensuring that the bases of the p-DNA have appropriate alignment to be accessible for hybridization. Layer-by-layer characterization of the electrode is performed by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) in the presence of [Fe(CN)(6)](3-) and [Ru(NH(3))(6)](3+) as anionic and cationic non-intercalative redox probes, respectively. Whereas, detection of the hybridization between p-DNA and target DNA (t-DNA) is probed using methylene blue (MB) and anthraquinone disulfonic acid (AQDS) as cationic and anionic intercalators, respectively. The variations of charge transfer resistance are found to be linearly related to the logarithm of the complementary DNA (c-DNA) concentration, from 1.0 x 10(-10) to 1.0 x 10(-6) M, with a detection limit of 8.5 x 10(-11) M using AQDS. Other merits of the sensor include: good sensitivity, selectivity in detection of c-DNA from mismatch and non-complementary strands, ease switching to different t-DNA detections, and having cheap preparation method.

• 出版日期2011-12-15