Artigo de eletroquímica

Biosensors and Bioelectronics 25 (2010) 2296–2301

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Biosensors and Bioelectronics journal homepage: www.elsevier.com/locate/bios

Dithiobis(succinimidyl propionate) modified gold microarray electrode based electrochemical immunosensor for ultrasensitive detection of cortisol
Sunil K. Arya a,∗ , Ganna Chornokur a , Manju Venugopal b , Shekhar Bhansali a,∗ a b

Bio-MEMS and Microsystem Lab, Department of Electrical Engineering, University of South Florida, 4202 E. Fowler Avenue, ENB 118, Tampa, FL 33620, United States Guided Therapeutics Inc., 5835 Peachtree Corners East, Suite D, Norcross, GA 30092, United States

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Gold microelectrode arrays functionalized with dithiobis(succinimidyl propionate) self-assembled monolayer (SAM) have been used to fabricate an ultrasensitive, disposable, electrochemical cortisol immunosensor. Cortisol specific monoclonal antibody (C-Mab) was covalently immobilized on the surface of gold microelectrode array and the sensors were exposed to solutions with different cortisol concentration. After C-Mab binding, unreacted active groups of DTSP were blocked using ethanol amine (EA) and label-free electrochemical impedance (EIS) technique was used to determine cortisol concentration. EIS results confirmed that EA/C-Mab/DTSP/Au based biosensor can accurately detect cortisol in the range of 1 pM–100 nM. The biosensor was successfully used for the measurement of cortisol in interstitial fluid in vitro. This research establishes the feasibility of using impedance based biosensor architecture for disposable, wearable cortisol detector. © 2010 Elsevier B.V. All rights reserved.

Article history: Received 22 December 2009 Received in revised form 9 March 2010 Accepted 10 March 2010 Available online 18 March 2010 Keywords: Cortisol Self-assembled monolayer Electrochemical impedance Immunosensor Dithiobis(succinimidyl propionate) Disposable biosensor

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