title: Graphene-based polyaniline arrays for deoxyribonucleic acid electrochemical sensor: effect of nanostructure on sensitivity.
abstract: DNA detection sensitivity can be improved by carefully controlling the texture of the sensor substrate, which was normally investigated on metal or metal oxide nanostructured platform. Morphology effects on the biofunctionalization of polymer micro/nanoelectrodes have not been investigated in detail. To extend this topic, we used graphene oxide (GNO) as the supporting material to prepare graphene-based polyaniline nanocomposites with different morphologies as a model for comparing their DNA sensing behaviors. Owing to GNO serving as an excellent support or template for nucleation and growth of polyaniline (PANI), PANI nanostructures grown on GNO substrate were successfully obtained. However, if GNO supporting was absent, the obtained PANI nanowires showed a connected network. Furthermore, adjustment of reaction time can be used for dominating the topographies of PANI-GNO nanocomposites, meaning that different reaction times resulted in various formations of PANI-GNO nanocomposites, including small horns (5 and 12 h), vertical arrays (18 h), and nanotips (24 h). The next-step electrochemical data showed that the DNA electrochemical sensors constructed on the different morphologies possessed different ssDNA surface coverage and hybridization efficiency. Compared with other morphologies of PANI-GNO nanocomposite (5, 12, and 24 h), vertical arrays (18 h) exhibited the highest sensitivity (2.08 × 10(-16) M, 2 orders of magnitude lower than others). It is can be concluded that this nanocomposite with higher surface area and more accessible space can provide an optimal balance for DNA immobilization and DNA hybridization detection.
authors.affiliation: Key Laboratory of Eco-Chemical Engineering (Ministry of Education), College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology , Qingdao 266042, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Yang
authors.forename: Le
authors.initials: L
authors.lastname: Meng
authors.forename: Jinlong
authors.initials: J
authors.lastname: Zhao
authors.forename: Xinxing
authors.initials: X
authors.lastname: Wang
authors.forename: Kui
authors.initials: K
authors.lastname: Jiao
mesh_terms: D000814:Aniline Compounds / Q000737:chemistry*; D004247:DNA / Q000032:analysis*; D004277:DNA, Single-Stranded / Q000737:chemistry; D055664:Electrochemical Techniques / Q000295:instrumentation / Q000379:methods*; D006108:Graphite / Q000737:chemistry*; D061925:Immobilized Nucleic Acids / Q000737:chemistry; D049329:Nanostructures / Q000737:chemistry*; D012680:Sensitivity and Specificity
chemical_list: D000814:Aniline Compounds; D004277:DNA, Single-Stranded; D061925:Immobilized Nucleic Acids; C416807:polyaniline; D006108:Graphite; D004247:DNA
keywords: differential pulse voltammogram; graphene oxide; hybridization efficiency; nanostructured material; polyaniline; ssDNA surface coverage