Electrochemical determination of paraquat using a DNA-modified carbon ionic liquid electrode

• Published in: Mikrochimica acta (1966) 2011-07, Vol.174 (1-2), p.89-95
• Main Authors: Mai, Nannan, Liu, Xiaoying, Wei, Wanzhi, Luo, Shenglian, Liu, Wei
• Format: Article
• Language: English
• Subjects: Analytical Chemistry; Biological and medical sciences; Biosensors; Biotechnology; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Detectors; DNA; Electric properties; Electrochemical methods; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; General, instrumentation; Herbicides; Methods. Procedures. Technologies; Microengineering; Nanochemistry; Nanotechnology; Original Paper; Various methods and equipments
• ISSN: 0026-3672; 1436-5073
• DOI: 10.1007/s00604-011-0602-7

Deoxyribonucleic acid (DNA) was electrochemically deposited on a carbon ionic liquid electrode to give a biosensor with excellent redox activity towards paraquat as shown by cyclic voltammetry and differential pulse voltammetry. Experimental conditions were optimized with respect to sensing paraquat by varying the electrochemical parameters, solution pH, and accumulation time of DNA. Under the optimized conditions, a linear relation exists between the reduction peak current and the concentration of paraquat in the range from 5 × 10 −8 mol L −1 to 7 × 10 −5 mol L −1 , with a detection limit of 3.6 × 10 −9 mol L −1 . The utility of the method is illustrated by successful analysis of paraquat in spiked real water samples. Figure The DNA was electrodeposited onto the CILE under +1.5 V for 1200 s. The electrochemical behaviors of paraquat on the modified electrode had been studied by cyclic voltammetry and differential pulse voltammetry. Five ml phosphate buffer (pH 7.0) solution was added into an electrochemical cell (10 ml) and then paraquat was successfully added into the cell. The differential pulse voltammograms were recorded when swept from −0.8 V to −0.3 V. The peak currents at about −0.63 V for paraquat were measured.