DNA biosensor based on a glassy carbon electrode modified with electropolymerized Eriochrome Black T

• Published in: Mikrochimica acta (1966) Vol. 181; no. 1-2; pp. 155 - 162
• Main Authors: Wang, Liheng, Liao, Xiaolei, Ding, Yingtao, Gao, Fei, Wang, Qingxiang
• Format: Journal Article
• Language: English
• Published: Vienna Springer Vienna 2014; Springer
• Subjects: Analytical Chemistry; Atomic force microscopy; Biosensors; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Covalence; Density; Deoxyribonucleic acid; Detectors; DNA; Electrochemical reactions; Electrochemistry; Electrodes; Ethylenediaminetetraacetic acid; Glassy carbon; Immobilization; Methylene blue; Microengineering; Nanochemistry; Nanotechnology; Original Paper; Eriochrome black T; DNA biosensor; Electropolymerization; Methylene blue
• ISSN: 0026-3672; 1436-5073
• DOI: 10.1007/s00604-013-1085-5

We report on an electrochemical DNA biosensor consisting of a glassy carbon electrode modified with a film of electropolymerized Eriochrome Black T (pEBT) that serves as a functional platform for the immobilization of probe DNA. pEBT was deposited via cyclic voltammetry, and the amino-modified DNA capture probe was covalently linked to the surface via a sulfanilamide coupling reaction. The single step of the assembly process was monitored by atomic force microscopy and electrochemistry. The surface density of DNA probe on the biosensor interface was calculated to be 1.7 × 10 −10  mol cm −2 using methylene blue as an electroactive probe. Hybridization experiments showed the peak currents of methylene blue to decrease with increasing concentration of complementary sequence in the range from 5.0 f. to 5.0 pM. The detection limit is as low as 0.11 fM. Selectivity studies showed that the biosensor can discriminate a fully complementary sequence from a single-base mismatch, three-base mismatch, and a fully non-complementary sequence. The biosensor displays good stability and can be regenerated due to the beneficial effects of electropolymerization and covalent immobilization of probe DNA. Figure A novel DNA biosensor was fabricated through a facile sulfamide coupling reaction between probe DNA and eriochrome black T that electropolymerized on a glassy carbon electrode