title: Label-free impedimetric thrombin sensor based on poly(pyrrole-nitrilotriacetic acid)-aptamer film.
abstract: A label-free and highly sensitive impedimetric aptasensor was developed based on electropolymerized film for the determination of thrombin. The first step is the electrogeneration of a poly(pyrrole-nitrilotriacetic acid) (poly(pyrrole-NTA)) film onto the surface of electrodes followed by complexation of Cu(2+) ions. Then, the histidine labeled thrombin aptamer was immobilized onto the electrode through coordination of the histidine groups on the NTA-Cu(2+) complex. The aptamer sensor was applied for the detection and quantification of thrombin via impedimetric detection without a labeling step. A linear quantification of thrombin was obtained in the range 4.7×10(-12)-5.0×10(-10) mol L(-1) with a sensitivity of 2838 Ω/log unit (R(2)=0.9984). The impedance modulus at 0.3 Hz as a function of thrombin concentration was used to elaborate a similar linear relationship from 4.7×10(-12) to 5×10(-10) mol L(-1). In addition, aptamer-poly(pyrrole-NTA) electrodes incubated for 40 min in aqueous solutions of bovine serum albumin (BSA), lysozyme and IgG (5×10(-7) mol L(-1)) did not exhibit non-specific adsorption of proteins. Moreover, it has been demonstrated that the selective sensor can be regenerated several times with a good reproducibility.
authors.affiliation: Département de Chimie Moléculaire, UMR-5250, ICMG FR-2607, CNRS, Université Joseph Fourier BP 53, 38041 Grenoble Cédex 9, France.
authors.forename: Hui
authors.initials: H
authors.lastname: Xu
authors.forename: Karine
authors.initials: K
authors.lastname: Gorgy
authors.forename: Chantal
authors.initials: C
authors.lastname: Gondran
authors.forename: Alan
authors.initials: A
authors.lastname: Le Goff
authors.forename: Nicolas
authors.initials: N
authors.lastname: Spinelli
authors.forename: Christian
authors.initials: C
authors.lastname: Lopez
authors.forename: Eric
authors.initials: E
authors.lastname: Defrancq
authors.forename: Serge
authors.initials: S
authors.lastname: Cosnier
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry*; D015374:Biosensing Techniques / Q000295:instrumentation*; D001780:Blood Coagulation Tests / Q000295:instrumentation; D003217:Conductometry / Q000295:instrumentation*; D004566:Electrodes; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008567:Membranes, Artificial; D009571:Nitrilotriacetic Acid / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D011758:Pyrroles / Q000737:chemistry*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013194:Staining and Labeling; D013917:Thrombin / Q000032:analysis*
chemical_list: D052157:Aptamers, Nucleotide; D008567:Membranes, Artificial; D011108:Polymers; D011758:Pyrroles; C067635:polypyrrole; D013917:Thrombin; D009571:Nitrilotriacetic Acid