Development of An Electrochemical Immunosensor for Environmental Monitoring of Polychlorinated Biphenyls (PCBs) in Soil Environment
dc.contributor.advisor | Maguire, Anita | |
dc.contributor.author | Alsefri, Samia | |
dc.date.accessioned | 2023-11-23T09:49:34Z | |
dc.date.available | 2023-11-23T09:49:34Z | |
dc.date.issued | 2023-04-24 | |
dc.description.abstract | Polychlorinated biphenyls, PCBs are a type of chemical contaminant known as persistent organic pollutants (POPs). They consist of biphenyl molecules covalently bonded with one to ten chlorine atoms. PCBs pose a threat to ecosystems and food safety due to their high toxicity, long-term stability, poor degradation, and bioaccumulation. The current methods, although sensitive, have their limitations, for example, time-consuming, laborious, and costly. Further, the instrumentation cannot be used for on-site analysis. The aim of this research is to develop a novel electrochemical method that will be capable of providing a direct, portable, cost-effective, and easy method for analysing and monitoring PCBs in the environment. For the first time, a self-assembled monolayer was used to modify an electrode as a method for fabricating a transducer for detection of PCBs by using a gold electrode, it was modified with 11- mercaptoundecanoic acid (11-MUA), and the activation of the carboxylic acid terminal was performed by cross-linking 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and N-hyrodsuccinmide (NHS). The electrochemical behaviour of the electrode was investigated by CV (Cyclic Voltammetry), LSV (Linear Sweep Voltammetry) and EIS (Electrochemical Impedance Spectroscopy) using a ferrocyanide/ferricyanide redox pair. It was found that the indirect competitive assay showed the best performance for Aroclor1254 detection, with a commercial Polyclonal chicken antibody (IgY) specific to PCB was used as primary antibody. The limit of detection was found at 0.20 ng/ml using bare gold electrode. However, the sensitivity of the sensor was increased after the electrode surface modification was found at 0.09 ng/ml. A novel electrochemical immunosensor method showed a good performance with a 3-fold decrease in sensitivity achieved after the surface modification. The electrode coated with coating conjugate was found stable for more than 25 days at 4 ˚C. In conclusion, this Ph.D. thesis demonstrates that the integration of electrochemical techniques with immunoassay methods can achieve detection limits as low as required for in-situ and real-time analysis of soil samples. It was found that the electrochemical immunosensor method showed better results compared to ELISA and that was verified with GC-MS. The usage of this a novel electrochemical immunosensor as a complement to the electrochemical studies not only enhanced the quality of the research but also contributed to the construction and improvement of immunosensors. As a result, they represent an accurate and a new robust method that can be applied to microsensors and microfluidic systems for the effective control and prevention of PCBs in the environment. | |
dc.format.extent | 348 | |
dc.identifier.uri | https://hdl.handle.net/20.500.14154/69825 | |
dc.language.iso | en | |
dc.publisher | Saudi Digital Library | |
dc.subject | electrochemical | |
dc.subject | ELISA | |
dc.subject | Immunosensor | |
dc.subject | GC-MS | |
dc.title | Development of An Electrochemical Immunosensor for Environmental Monitoring of Polychlorinated Biphenyls (PCBs) in Soil Environment | |
dc.type | Thesis | |
sdl.degree.department | Chemistry | |
sdl.degree.discipline | Analytical Chemistry | |
sdl.degree.grantor | University College Cork | |
sdl.degree.name | Doctor of Philosophy |