title: Antibody functionalized interdigitated micro-electrode (IDmicroE) based impedimetric cortisol biosensor.
abstract: This paper reports on an ultrasensitive, disposable, impedimetric biosensor for cortisol detection. C-Mab (a Cortisol specific monoclonal antibody) was covalently immobilized via amide bond on the surface of the interdigitated micro-electrodes (IDmicroEs) functionalized with dithiobis(succinimidyl propionate) (DTSP) self-assembled monolayer (SAM). After C-Mab binding, unreacted active groups of DTSP were blocked using ethanolamine (EA) and glycine (Gly) mixture. The disposable sensors were exposed to solutions with different cortisol concentrations and a label-free electrochemical impedance (EIS) technique was used to determine the cortisol concentration. EIS results confirm that the EA-Gly/C-Mab/DTSP/IDmicroE based biosensor exhibited the sensitivity of 2.855 kohms M(-1) and could accurately detect cortisol in the range of 1 pM to 10 nM in saliva. This work establishes the feasibility of using an impedance based biosensor as a disposable cortisol detector, capable of working with complex bodily fluids (e.g., saliva). The architecture enables the use of cortisol sensors at point-of-care.
authors.affiliation: BioMEMS and Microsystems Lab, Department of Electrical Engineering, University of South Florida, 4202 E. Fowler Avenue, ENB 118, Tampa, FL 33620, USA. sunilarya333@gmail.com
authors.forename: Sunil K
authors.initials: SK
authors.lastname: Arya
authors.forename: Ganna
authors.initials: G
authors.lastname: Chornokur
authors.forename: Manju
authors.initials: M
authors.lastname: Venugopal
authors.forename: Shekhar
authors.initials: S
authors.lastname: Bhansali
mesh_terms: D000911:Antibodies, Monoclonal / Q000737:chemistry* / Q000276:immunology*; D015374:Biosensing Techniques; D004563:Electrochemistry; D004797:Enzyme-Linked Immunosorbent Assay; D006854:Hydrocortisone / Q000032:analysis* / Q000276:immunology; D008567:Membranes, Artificial; D008839:Microelectrodes; D013388:Succinimides / Q000737:chemistry; D013499:Surface Properties
chemical_list: D000911:Antibodies, Monoclonal; D008567:Membranes, Artificial; D013388:Succinimides; C011240:dithiobis(succinimidylpropionate); D006854:Hydrocortisone