A Reusable Impedimetric Aptasensor for Detection of Thrombin Employing a Graphite-Epoxy Composite Electrode
Ocaña Tejada, Cristina (Universitat Autònoma de Barcelona. Departament de Química)
Pacios Pujadó, Merce (Universitat Autònoma de Barcelona. Departament de Química)
Valle Zafra, Manuel del (Universitat Autònoma de Barcelona. Departament de Química)

Data:	2012
Resum:	Here, we report the application of a label-free electrochemical aptasensor based on a graphite-epoxy composite electrode for the detection of thrombin; in this work, aptamers were immobilized onto the electrodes surface using wet physical adsorption. The detection principle is based on the changes of the interfacial properties of the electrode; these were probed in the presence of the reversible redox couple [Fe(CN)6]3−/[Fe(CN)6]4− using impedance measurements. The electrode surface was partially blocked due to formation of aptamer-thrombin complex, resulting in an increase of the interfacial electron-transfer resistance detected by Electrochemical Impedance Spectroscopy (EIS). The aptasensor showed a linear response for thrombin in the range of 7. 5 pM to 75 pM and a detection limit of 4. 5 pM. The aptasensor was regenerated by breaking the complex formed between the aptamer and thrombin using 2. 0 M NaCl solution at 42 °C, showing its operation for different cycles. The interference response caused by main proteins in serum has been characterized.
Ajuts:	Ministerio de Ciencia e Innovación CTQ2010-17099
Drets:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan es reconegui l'autoria de l'obra original.
Llengua:	Anglès
Document:	Article ; recerca ; Versió publicada
Matèria:	Aptamer ; Thrombin ; Electrochemical impedance spectroscopy ; Labeless ; Adsorption
Publicat a:	Sensors (Basel, Switzerland), Vol. 12 (March 2012) , p. 3037-3048, ISSN 1424-8220

DOI: 10.3390/s120303037
PMID: 22736991

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