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Electrochemical ochratoxin a immunosensors based on polyaniline nanocomposites templated with amine- and sulphate-functionalised polystyrene latex beads

Philosophiae Doctor - PhD / Polyaniline nanocomposites doped with poly(vinylsulphonate) (PV-SO3) and nanostructured polystyrene (PSNP) latex beads functionalized with amine (PSNP-NH2) and sulphate ((PSNP-OSO3) were prepared and characterised for use as nitrite electro-catalytic chemosensors and ochratoxin A immunosensors. The resultant polyaniline electrocatalytic chemosensors (PANI, PANI|PSNP-NH2 or PANI|PSNP-OSO3
−) were characterized by cyclic voltammetry (CV), ultraviolet-visible (UV-Vis) spectroscopy and scanning electron microscopy (SEM). Brown-Anson analysis of the multi-scan rate CV responses of the various PANI films gave surface concentrations in the order of 10−8 mol/cm. UV-vis spectra of the PANI films dissolved in dimethyl sulphoxide showed typical strong absorbance maxima at 480 and 740 nm associated with benzenoid p-p* transition and quinoid excitons of polyaniline, respectively. The SEM images of the PANI nanocomposite films showed cauliflower-like structures that were <100 nm in diameter. When applied as electrochemical nitrite sensors, sensitivity values of 60, 40 and 30 μA/mM with corresponding limits of detection of 7.4, 9.2 and 38.2 μM NO2 −, were obtained for electrodes, PANI|PSNP-NH2, PANI and PANI|PSNP-SO3
−; respectively. Immobilisation of ochratoxin A antibody onto PANI|PSNP-NH2, PANI and PANI|PSNPSO3 - resulted in the fabrication of immunosensors. / South Africa

Identiferoai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:uwc/oai:etd.uwc.ac.za:11394/2559
Date January 2010
CreatorsMuchindu, Munkombwe
ContributorsIwuoha, Emmanuel, Jahed, Nazeem, Faculty of Science
PublisherUniversity of the Western Cape
Source SetsSouth African National ETD Portal
LanguageEnglish
Detected LanguageEnglish
TypeThesis
RightsUniversity of the Western Cape

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