title: Impedance spectroscopy analysis of human odorant binding proteins immobilized on nanopore arrays for biochemical detection.
abstract: Human odorant-binding proteins (hOBPs) not only can bind and transport odorants in the surrounding environment for sensing smells, but also play important roles in transmitting lots of biomolecules in different organs. Utilizing the properties of hOBPs, an electrochemical biosensor with nanopore array was developed to detect specific biomolecular ligands, such as aldehydes and fatty acids. The highly ordered nanopores of anodic aluminum oxide with diameter of 20-40 nm were fabricated with two-step oxidation. Through 2-carboxyethyl phosphonic acid, hOBPs were self-assembled on nanopores as the sensing membrane. With nanopore arrays, the impedance spectra showed quite different electron transfer processes in the frequency spectra, which could be characterized by the electron transfer resistance and electrical resistance of the porous membrane. Under stimulation of biomolecular ligands, series resistance of nanopores and hOBPs increased and showed a concentration-dependence feature, while the electron transfer resistance hardly changed. The nanopore based biosensor could sensitively detect biological ligands of benzaldehyde, docosahexaenoic acid, and lauric acid, which were closely related to or were potential biomarkers for cancers and other serious diseases. Equipped with hOBPs, the sensor exhibited promising potentials both in odorant and biomolecule detection for olfactory biosensing and in disease diagnosis and evaluation for biochemical detection.
authors.affiliation: Biosensor National Special Laboratory, Key Laboratory for Biomedical Engineering of Education Ministry, Department of Biomedical Engineering, Zhejiang University, Hangzhou 310027, PR China.
authors.forename: Yanli
authors.initials: Y
authors.lastname: Lu
authors.affiliation: Biosensor National Special Laboratory, Key Laboratory for Biomedical Engineering of Education Ministry, Department of Biomedical Engineering, Zhejiang University, Hangzhou 310027, PR China.
authors.forename: Diming
authors.initials: D
authors.lastname: Zhang
authors.affiliation: Biosensor National Special Laboratory, Key Laboratory for Biomedical Engineering of Education Ministry, Department of Biomedical Engineering, Zhejiang University, Hangzhou 310027, PR China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Biosensor National Special Laboratory, Key Laboratory for Biomedical Engineering of Education Ministry, Department of Biomedical Engineering, Zhejiang University, Hangzhou 310027, PR China.
authors.forename: Yixuan
authors.initials: Y
authors.lastname: Huang
authors.affiliation: Shangyu People's Hospital of Zhejiang Province, Shangyu 312000, PR China.
authors.forename: Senbiao
authors.initials: S
authors.lastname: Luo
authors.affiliation: Biosensor National Special Laboratory, Key Laboratory for Biomedical Engineering of Education Ministry, Department of Biomedical Engineering, Zhejiang University, Hangzhou 310027, PR China.
authors.forename: Yao
authors.initials: Y
authors.lastname: Yao
authors.affiliation: Biosensor National Special Laboratory, Key Laboratory for Biomedical Engineering of Education Ministry, Department of Biomedical Engineering, Zhejiang University, Hangzhou 310027, PR China.
authors.forename: Shuang
authors.initials: S
authors.lastname: Li
authors.affiliation: Biosensor National Special Laboratory, Key Laboratory for Biomedical Engineering of Education Ministry, Department of Biomedical Engineering, Zhejiang University, Hangzhou 310027, PR China. Electronic address: qjliu@zju.edu.cn.
authors.forename: Qingjun
authors.initials: Q
authors.lastname: Liu
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry; D001547:Benzaldehydes / Q000737:chemistry*; D015374:Biosensing Techniques; D058266:Dielectric Spectroscopy; D004281:Docosahexaenoic Acids / Q000737:chemistry*; D006801:Humans; D055767:Immobilized Proteins / Q000737:chemistry; D007850:Lauric Acids / Q000737:chemistry*; D008024:Ligands; D058608:Nanopores; D011485:Protein Binding; D018035:Receptors, Odorant / Q000737:chemistry*
chemical_list: D001547:Benzaldehydes; D055767:Immobilized Proteins; D007850:Lauric Acids; D008024:Ligands; D018035:Receptors, Odorant; C045648:odorant-binding protein; C030358:lauric acid; D004281:Docosahexaenoic Acids; D000537:Aluminum Oxide; C032175:benzaldehyde
keywords: Biochemical detection; Biosensor; Human odorant binding protein (hOBPs); Impedance spectroscopy; Nanopore array