Novel 3-mercaptopropionic acid capped iridium selenide quantum dots modified electrochemical immunosensor for the detection of fish toxin, nodularin

>Magister Scientiae - MSc / A novel 3-mercaptopropionic acid capped iridium selenide quantum dots based label free impedimetric immunosensor was successfully constructed. The 3-mercaptopropionic acid capped iridium selenide quantum dots synthesized were studied using HRTEM, revealing the formation of very small sizes, of about 3 nm. The optical Uv-Vis absorption wavelength of the quantum dots is blue-shifted, a phenomenon explained by the effective mass approximation (EMA) for semiconducting materials with sizes below 10 nm. Using cyclic voltammetry it is noted that the quantum dots have interesting electro-catalytical properties. The immunosensor proved to be sensitive towards nodularin, with a very low detection limit of 0.009 ng/mL and is significantly lower than the recent anti-nodularin
ELISA kit developed by (Zhou et al., 2011) which has a detection limit of 0.16 ng/mL.Also the dection limit of the immunosensor is below the South African guideline value for microcystin-LR (0-0.8) μg/L (DWAF; 1996). The calibration curve of the 3MPA-GaSe nanocrystal based biosensor was successfully
constructed, which exhibited a trend described by Michaelis-Menten, a typical behaviour of enzymatic biosensors. The detection limit of the biosensor is 0.004 nM and is significantly lower than the action limit of 17beta-estradiol, (1.47 x 10-10 M).

Identiferoai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:uwc/oai:etd.uwc.ac.za:11394/4616
Date January 2012
CreatorsNxusani, Ezo
ContributorsIwuoha, Emmanuel, Baker, Priscilla
PublisherUniversity of the Western Cape
Source SetsSouth African National ETD Portal
LanguageEnglish
Detected LanguageEnglish
TypeThesis
RightsUniversity of the Western Cape

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