Electrochemical Immunosensor based on Cyclodextrin Supramolecular interactions for the detection of human chorionic gonadotropin

dc.contributor.advisorIwuoha, Emmanuel I.
dc.contributor.advisorO’Sullivan, Ciara K.
dc.contributor.authorWilson, Lindsay
dc.date.accessioned2019-05-07T07:20:08Z
dc.date.accessioned2024-05-09T10:50:26Z
dc.date.available2019-05-07T07:20:08Z
dc.date.available2024-05-09T10:50:26Z
dc.date.issued2012
dc.description>Magister Scientiae - MScen_US
dc.description.abstractGlucose oxidase (GOx) and horseradish peroxidase (HRP) are important enzymes for the development of amperometric enzyme linked immunosensors. The selectivity of each enzyme towards its analyte deepens its importance in determining the sensitivity of the resultant immunosensor. In designing immunosensors that have customized transducer surfaces, the incorporation with FAD and iron based enzymes ensures that electron kinetics remains optimal for electrochemical measurement. Various different immobilization strategies are used to produce response signals directly proportional to the concentration of analyte with minimal interferences. The combination of self-assembled monolayers and supramolecular chemistry affords stability and simplicity in immunosensor design. In this work, two electrochemical strategies for the detection of human chorionic gonadotropin(hCG) is presented. This involves the modification of a gold surface with a thiolated β-cyclodextrin epichlorohydrin polymer (βCDPSH) to form a supramolecular inclusion complex with ferrocene (Fc)-functionalised carboxymethyl cellulose polymer (CMC). Cyclic voltammetry indicated that ferrocene is in close proximity to the electrode surface due to the supramolecular complex formed with βCDPSH. Furthermore, strategy (a) for the detection of hCG used α-antihCG labelled (HRP) as reporter conjugate. Strategy (b) maintained the CMC bifunctionalised with Fc and recognition antibody for hCG hormone. However, the system was functionalised with a HRP enzyme and detection is done by using GOx reporter conjugates for in situ production of hydrogen peroxide. The reduction of H2O2 was used for the amperometric detection of hCG by applying a potential of 200 mV. The sensitivity and limit of detection of both strategies were calculated from calibration plots. For strategy (a) the LOD was found to be 3.7283 ng/mL corresponding to 33.56 mIU/mL and a sensitivity of 0.0914 nA ng-1 mL-1. The corresponding values for strategy (b) are 700 pg/mL (6.3 mIU/mL) and 0.94 nA ng-1 mL-1.en_US
dc.identifier.urihttps://hdl.handle.net/10566/14521
dc.language.isoenen_US
dc.publisherUniversity of the Western Capeen_US
dc.rights.holderUniversity of the Western Capeen_US
dc.subjectBiosensoren_US
dc.subjectImmunosensoren_US
dc.subjectβ-Cyclodextrinen_US
dc.subjectβ-Cyclodextrin epichlorohydrin polymeren_US
dc.subjectFerroceneen_US
dc.subjectCarboxymethyl celluloseen_US
dc.subjectSupramolecularen_US
dc.subjectHost-guesten_US
dc.subjectSelf-assembled monolayersen_US
dc.subjectBienzymaticen_US
dc.subjectCo-operative effecten_US
dc.subjectCyclic Voltammetryen_US
dc.subjectSquare Wave Voltammetryen_US
dc.subjectEnzyme Linked Immunosorbent Assayen_US
dc.subjectAmperometricen_US
dc.subjectHuman Chorionic Gonadotropinen_US
dc.titleElectrochemical Immunosensor based on Cyclodextrin Supramolecular interactions for the detection of human chorionic gonadotropinen_US
dc.typeThesisen_US

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