title: Comparative studies on zirconia and graphene composites obtained by one-step and stepwise electrodeposition for deoxyribonucleic acid sensing.
abstract: In this paper, the comparison of two kinds of electrochemically reduced graphene oxide (ERGNO) and zirconia composites, obtained by one-step (ZrO2-ERGNO) and stepwise (ZrO2/ERGNO) electrodeposition for DNA sensing, is systematically studied. The resulting composites were characterized by scanning electron microscopy, cyclic voltammetry, and differential pulse voltammetry. The results indicated that the ZrO2-ERGNO presented fine globular nanostructure. However, ZrO2/ERGNO presented agglomerate massive microstructure due to the absence of the oxygen-containing groups of graphene oxide, confirming the oxygen-containing groups provided a better affinity for the deposition of ZrO2. Due to the strong binding of the phosphate groups of DNA with the zirconia film, DNA probes were attached on the ZrO2-based composites. ZrO2-ERGNO/Au owning fine nanostructure presented larger surface area than microstructured ZrO2/ERGNO/Au. Moreover, compared with microstructured ZrO2/ERGNO, the nanostructured ZrO2-ERGNO provided more accessible space for immobilized DNA probe hybridization with target sequence, which consequently resulted in higher hybridization efficiency. Therefore, the ZrO2-ERGNO was chosen for fabricating DNA sensor with a limit of detection 1.21×10(-14) mol L(-1).
authors.affiliation: Key Laboratory of Eco-chemical Engineering (Ministry of Education), College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Yang
authors.forename: Xiuhong
authors.initials: X
authors.lastname: Guo
authors.forename: Qianqian
authors.initials: Q
authors.lastname: Kong
authors.forename: Ruirui
authors.initials: R
authors.lastname: Yang
authors.forename: Qianhe
authors.initials: Q
authors.lastname: Li
authors.forename: Kui
authors.initials: K
authors.lastname: Jiao
mesh_terms: D015374:Biosensing Techniques / Q000379:methods* / Q000592:standards; D004247:DNA / Q000032:analysis*; D015342:DNA Probes / Q000737:chemistry; D004595:Electroplating / Q000379:methods* / Q000592:standards; D006108:Graphite / Q000737:chemistry*; D015040:Zirconium / Q000737:chemistry*
chemical_list: D015342:DNA Probes; D006108:Graphite; D004247:DNA; D015040:Zirconium; C028541:zirconium oxide