title: Label-free aptamer-based electrochemical impedance biosensor for 17β-estradiol.
abstract: A novel aptamer-based label-free electrochemical impedance spectroscopy biosensor for 17β-estradiol has been fabricated. The aptamers were firstly immobilized on the gold electrode through Au-S interaction; the aptamer probe was then bound with the addition of 17β-estradiol to form the estradiol/aptamer complex on the electrode surface. This leads to a significantly larger interfacial electron transfer resistance than that without the addition of 17β-estradiol. The change in the resistance had a linear relationship with 17β-estradiol concentration in the range of 1.0 × 10(-8) to 1.0 × 10(-11) mol L(-1), with a detection limit of 2.0 × 10(-12) mol L(-1). The biosensor showed high selectivity to 17β-estradiol and good stability. The designed biosensor has been applied to detect 17β-estradiol in human urine with satisfactory results.
authors.affiliation: Ministry of Education Key Laboratory of Analysis and Detection for Food Safety, Fuzhou University, Fuzhou, Fujian 350002, China. zylin@fzu.edu.cn
authors.forename: Zhenyu
authors.initials: Z
authors.lastname: Lin
authors.forename: Lifen
authors.initials: L
authors.lastname: Chen
authors.forename: Guiyun
authors.initials: G
authors.lastname: Zhang
authors.forename: Qida
authors.initials: Q
authors.lastname: Liu
authors.forename: Bin
authors.initials: B
authors.lastname: Qiu
authors.forename: Zongwei
authors.initials: Z
authors.lastname: Cai
authors.forename: Guonan
authors.initials: G
authors.lastname: Chen
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry; D015374:Biosensing Techniques / Q000379:methods*; D058266:Dielectric Spectroscopy / Q000379:methods*; D055664:Electrochemical Techniques / Q000379:methods; D004563:Electrochemistry / Q000379:methods; D004958:Estradiol / Q000652:urine*; D006046:Gold / Q000737:chemistry; D006801:Humans; D057230:Limit of Detection; D012680:Sensitivity and Specificity
chemical_list: D052157:Aptamers, Nucleotide; D004958:Estradiol; D006046:Gold