title: Development of a novel electrochemical DNA biosensor based on elongated hexagonal-pyramid CdS and poly-isonicotinic acid composite film.
abstract: Three CdS materials with different shapes (i.e., irregular, rod-like, and elongated hexagonal-pyramid) were hydrothermally synthesized through controlling the molar ratio of Cd(2+) to thiourea. Electrochemical experiments showed that the elongated hexagonal-pyramid CdS (eh-CdS) modified on glassy carbon electrode (GCE) had the higher electrical conductivity than the other two forms. Then the eh-CdS modified GCE was further modified with a layer of poly-isonicotinic acid (PIA) through electro-polymerization in IA solution to enhance the stability and functionality of the interface. The layer-by-layer modification process was characterized by atomic force microscopy and electrochemistry. Then 5'-amino functionalized DNA was immobilized on the electrode surface through coupling with the carboxylic groups derived from PIA-eh-CdS composite film. The hybridization performance of the developed biosensor was evaluated using methylene blue as redox indicator, and the results showed that the peak currents of methylene blue varied with target concentrations in a wide linear range from 1.0 × 10(-14)M to 1.0 × 10(-9)M with a low detection limit of 3.9 × 10(-15)M. The biosensor also showed high stability and good discrimination ability to the one-base, three-base mismatched and non-complementary sequence.
authors.affiliation: Department of Chemistry and Environment Science, Fujian Province University Key Laboratory of Analytical Science, Minnan Normal University, Zhangzhou 363000, PR China.
authors.forename: Delun
authors.initials: D
authors.lastname: Zheng
authors.affiliation: Department of Chemistry and Environment Science, Fujian Province University Key Laboratory of Analytical Science, Minnan Normal University, Zhangzhou 363000, PR China. Electronic address: axiang236@126.com.
authors.forename: Qingxiang
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Department of Chemistry and Environment Science, Fujian Province University Key Laboratory of Analytical Science, Minnan Normal University, Zhangzhou 363000, PR China.
authors.forename: Feng
authors.initials: F
authors.lastname: Gao
authors.affiliation: Department of Chemistry and Environment Science, Fujian Province University Key Laboratory of Analytical Science, Minnan Normal University, Zhangzhou 363000, PR China.
authors.forename: Qinghua
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Department of Chemistry and Environment Science, Fujian Province University Key Laboratory of Analytical Science, Minnan Normal University, Zhangzhou 363000, PR China.
authors.forename: Weiwei
authors.initials: W
authors.lastname: Qiu
authors.affiliation: Department of Chemistry and Environment Science, Fujian Province University Key Laboratory of Analytical Science, Minnan Normal University, Zhangzhou 363000, PR China.
authors.forename: Fei
authors.initials: F
authors.lastname: Gao
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D019187:Cadmium Compounds / Q000737:chemistry*; D003217:Conductometry / Q000295:instrumentation*; D004247:DNA / Q000032:analysis / Q000235:genetics*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007539:Isonicotinic Acids / Q000737:chemistry*; D020411:Oligonucleotide Array Sequence Analysis / Q000295:instrumentation*; D015203:Reproducibility of Results; D018036:Selenium Compounds / Q000737:chemistry*; D012680:Sensitivity and Specificity; D017422:Sequence Analysis, DNA / Q000295:instrumentation*
chemical_list: D019187:Cadmium Compounds; D007539:Isonicotinic Acids; D018036:Selenium Compounds; D004247:DNA; C058667:cadmium selenide
keywords: DNA biosensor; Electrochemical polymerization; Elongated hexagonal-pyramid CdS; Isonicotinic acid