The development of a biosensor for the early detection of pancreatic cancer

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dc.contributor.advisorPerold, Willemen_ZA
dc.contributor.advisorEngelbrecht, Anna-Marten_ZA
dc.contributor.authorEbrahim, Taskeenen_ZA
dc.contributor.otherStellenbosch University. Faculty of Engineering. Dept. of Electrical and Electronic Engineering.en_ZA
dc.date.accessioned2023-03-06T09:54:28Zen_ZA
dc.date.accessioned2023-05-18T07:08:33Zen_ZA
dc.date.available2023-03-06T09:54:28Zen_ZA
dc.date.available2023-05-18T07:08:33Zen_ZA
dc.date.issued2023-03en_ZA
dc.descriptionThesis (PhD)--Stellenbosch University, 2023.en_ZA
dc.description.abstractENGLISH ABSTRACT: Pancreatic cancer has one of the highest cancer mortality rates, as it is often detected in late stages. Current methods of detection include diagnostic imaging tests or laboratory intensive blood tests such as radioimmunoassays or ELISAs. Researchers have used biosensors for detection and monitoring of different medical conditions, as a more accessible and cheaper alternative. This project focuses on the design of a biosensor toward the early detection of pancreatic cancer, using Carbohydrate Antigen 19-9 (CA19-9) as the selected biomarker for the biosensor. Electrochemical impedance spectroscopy was identified as an appropriate transducer mechanism for this biosensor and uses gold interdigitated electrodes as a sensor transducer surface. Anti-CA19-9 antibodies were immobilized onto gold using covalent bonding and crosslinking chemistries, and binding was validated using fluorescence microscopy. After electrodes were electronically characterized to identify the appropriate impedance and frequency ranges, an impedance analyser was designed, fabricated, and tested, with added computation of complex capacitance. The impedance analyser was calibrated and tested relative to the PalmSens4 Electrochemical Interface. The designed impedance analyser showed mean impedance and phase errors of 0.538% and 0.381% respectively. Similarly, the accuracy of complex capacitance computation showed errors of 1.222% and 0.656% for real and imaginary components respectively. The impedance analyser differentiated between changes in concentration of phosphate buffered saline using complex capacitance. The biosensor was tested with five concentrations of CA19-9 and differentiated between concentrations above and below the thresholds for pancreatic cancer. The design of a novel impedance analyser utilizing complex capacitance computation for the quantification of CA19-9 using IDEs fabricated on an FR4 board is a unique contribution to biosensor research. en_ZA
dc.description.abstractAFRIKAANS OPSOMMING: Pankreaskanker het een van die hoogste kanker sterftesyfers omdat dit meestal te laat gediagnoseer word. Huidige deteksiemetodes sluit diagnostiese beeldvorming en intensiewe laboratorium bloedtoetse, soos radio-immunotoetse of ELISA’s, in. Navorsers gebruik biosensors vir die opsporing en monitering van mediese toestande reeds vir ’n geruime tyd, omdat dit meer toeganklik en bekostigbaar is. Hierdie projek fokus op die ontwerp van ’n biosensor vir die vroegtydige opsporing van pankreaskanker deur van Koolhidraat Antigeen 19-9 (KA19-9) as biomerker gebruik te maak. Elektrochemiese impedansie spektroskopie is ge¨ıdentifiseer as die geskikte omsetter vir die biosensor, en maak gebruik van goue interdigitale elektrodes as ’n sensor omsetter oppervlak. Anti-KA19-9 teenliggampies is op goud ge¨ımmobiliseer deur van kovalente bindings en kruisbindende chemie gebruik te maak, en die suksesvolle binding is deur fluoressensie mikroskopie geverifieer. Nadat die elektrodes elektroniese gekarakteriseer is om die toepaslike impedansie- en frekwensiebereik vas te stel, is ’n impedansie-analiseerder, wat ook komplekse kapasitansie kan bereken, ontwerp, gebou en getoets. Die ontwerpte impedansie-analiseerder is gekalibreer en getoets met die PalmSens4 Elektrochemiese tussenvlak as verwysing. Met die ontwerpte impedansie-analiseerder is gemiddelde impedansie- en fasefoute van 0.538% en 0.381%, onderskeidelik, verkry. Soortgelyk, is akkuraatheid van onderskeidelik 1.222% en 0.656% verkry vir die re¨ele en imaginˆere gedeeltes van die berekende komplekse kapasitansies. Die impedansie-analiseerder was in staat om verskille in die konsentrasie van fosfaat-gebufferde soutoplossing met behulp van berekende waardes van komplekse kapasitansie suksesvol te meet. Die biosensor is ook met vyf konsentrasies van KA19-9 getoets en kon suksesvol differensieer tussen konsentrasies bo en onder die drempel vir pankreaskanker. Die implementering van ’n unieke impedansie-analiseerder, wat van die berekening van komplekse kapasitansie gebruik maak om KA19-9 te kwantifiseer, en ook interdigitale elektrodes op ’n FR4 substraat gebruik as omsetter, is ’n unieke bydrae tot biosensor navorsing. af_ZA
dc.description.versionDoctoralen_ZA
dc.format.extentxvi, 153 pages : illustrations.en_ZA
dc.identifier.urihttp://hdl.handle.net/10019.1/127182en_ZA
dc.language.isoen_ZAen_ZA
dc.language.isoen_ZAen_ZA
dc.publisherStellenbosch : Stellenbosch Universityen_ZA
dc.rights.holderStellenbosch Universityen_ZA
dc.subjectThe development of a biosensor for the early detection of pancreatic canceren_ZA
dc.subject.lcshBiosensorsen_ZA
dc.subject.lcshPancreas – Cancer – Early detectionen_ZA
dc.subject.lcshRadioimmunoassayen_ZA
dc.subject.lcshImpedance spectroscopyeen_ZA
dc.titleThe development of a biosensor for the early detection of pancreatic canceren_ZA
dc.typeThesisen_ZA
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Doctoral Degrees (Electrical and Electronic Engineering)