title: Enhanced performance of nanocrystalline ZnO DNA biosensor via introducing electrochemical covalent biolinkers.
abstract: Zinc oxide (ZnO) is considered to be one of the most promising candidates for the third-generation DNA biosensor because of its good chemical stability, wonderful biocompatibility, easy surface modification, and numerous kinds of nanostructures. In this work, we report a new and simple method to modify ZnO surface for the immobilization of oligonucleotides by electrochemical covalent grafting of diazonium salts. The atomic force microscope, X-ray photoelectron spectroscopy, surface contact angle system, and electrochemical workstation were employed to characterize the functionalization process. Fluorescence results show that this kind of DNA biosensor from covalently linking strategy has an enhanced performance compared to that based on an electrostatic adsorption route. The functionalized ZnO biosensor has the capability to distinguish four-base mismatched, one-base mismatched, and complementary DNA sequences. Moreover, a linear relationship has been observed between the fluorescence intensity and the concentration of the complementary DNA in the solution within the range from 10(-6) to 10(-9) M, offering us a possibility in the qualitative determination of the level of target DNA.
authors: †Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Wenhua Road 72, 110016 Shenyang, China.
authors: Chun
authors: C
authors: Wang
authors: †Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Wenhua Road 72, 110016 Shenyang, China.
authors: Nan
authors: N
authors: Huang
authors: ‡Institute of Materials Engineering, University of Siegen, Paul-Bonatz-Str. 9-11, 57076 Siegen, Germany.
authors: Hao
authors: H
authors: Zhuang
authors: †Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Wenhua Road 72, 110016 Shenyang, China.|‡Institute of Materials Engineering, University of Siegen, Paul-Bonatz-Str. 9-11, 57076 Siegen, Germany.
authors: Xin
authors: X
authors: Jiang
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D003432:Cross-Linking Reagents / Q000737:chemistry; D004247:DNA / Q000032:analysis* / Q000235:genetics*; D004595:Electroplating / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008422:Materials Testing; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D020411:Oligonucleotide Array Sequence Analysis / Q000295:instrumentation; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence / Q000379:methods; D015034:Zinc Oxide / Q000737:chemistry*
chemical_list: D003432:Cross-Linking Reagents; D004247:DNA; D015034:Zinc Oxide
keywords: DNA biosensor; ZnO; covalent bond; electrochemistry; fluorescence; functionalization