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Development of a lab on a chip electrochemical immunosensor array for the detection of polycyclic aromatic hydrocarbons (PAHs) in environmental of water
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Date
2020-01
Authors
Felemban, Shifa Jameel
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Publisher
University College Cork
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Abstract
Polycyclic aromatic hydrocarbons (PAHs) are a very large group of organic compounds
made of carbon and hydrogen atoms. These compounds present an important impact as
environmental pollutants. They are a primary concern for human health, as PAHs have
been reported to increase the risk of cancer in humans. It is therefore of high importance
to avail of a method to detect them in any matter that humans may get in contact with,
such as food, soil and water. The European Drinking Water Directive (98/83/EC)
recommends a value of 0.01ng/ml as a limit for Benzo[a]pyrene (BaP) levels in drinking
water. Traditionally, detection of PAHs in the environment was done using commercial
equipment such as HPLC-fluorescence detection and Gas Chromatography-Mass
Spectrometry (GC-MS). However, these techniques are often expensive, use large
amounts of toxic solvents, are time-consuming, and non-portable [8,9]. In this research,
immunosensors were used for BaP determination in water sample. Immunosensors are
affinity biosensors based on the specific interaction between antigens and antibodies;
this interaction could be monitored by several techniques including electrochemistry.
Voltammetric detection with the immunosensor provides an approach, which could be
performed in small portable instrument for in-field measurements. Electrochemistry
technique has several advantages compared to other techniques; it is easy to apply and
also have the advantages of miniaturisation, portability, real measurement time, lowcost
production and fabrication without reducing their levels of detection or sensitivity.
This thesis is to address the shortcomings of the current techniques. The study presented
in this thesis described the development of the immunosensors with electrochemical
detection for detection of polycyclic aromatic hydrocarbon in environmental monitoring
of water. This work shows how the integration of electrochemical techniques with an
immunoassay method can reach limits of detection as low as required for the analysis of
water samples in situ and in real time. In particular, we targeted to detect the presence of
(BaP) in water. Results obtained by optical and electrochemical detections were
validated with Gas Chromatography-Mass Spectrometry (GC-MS). The usage of this
method as a complement to the electrochemical studies, not only increased the quality
of the research, but also helped in the construction and improvement of immunosensors.
They were not reliable, but also represent accurate characteristics to be employed in
miniaturised sensor and fluidic system. This thesis is organized in six chapters and a
brief explanation for each of them is shown below:
Chapter 1 is a general introduction about the essential concepts and conditions used in
this thesis. Chapter 2 offers an understanding of the key principles of optical
immunoassay involved in this thesis. An optical immunoassay using a 96-well
microtiter plate as a solid surface was developed. Chapter 3 the application of the
developed electrochemical immunosensors was discussed. Chapter 4, focuses on the
design, fabrication and characterization of a Q-sens (Lab On a Chip) that was developed
for use in electrochemical application. Chapter 5 demonstrates the validation study in
order to confirm that the applied developed method for a PAH was suitable for its
intended use. The validation could compare the reliability and sensitivity of the
developed results. Chapter 6 represents the conclusion and future perspectives. Basis:
The objective of the work presented is to develop an electrochemical sensing array to
detect PAHs in the environment, as they represent a toxic threat for health in water and
the current detection methods are time consuming and non-portable.
Hypothesis:
The research will focus on the integration of a sensor arrays with immunoassay and
electrochemical detection methods. Water samples will be spiked with PAHs and tested
using the immunosensor arrays. ELISA will be used to help validate the electrochemical
analysis This project show the work done towards the optimisation of the immunoassay
protocol for PAHs detection in water samples, and its transfer into a lab-on-a chip
application that has a particular focus on environmental screening.
Research strategy:
The first year aim of the research was to optimize ELISA reagents and detection
methods. The second year and first half of the third year of the research were for
integrating the immunoassay method with lab on a chip platform. The second half of the
third year was for the interfaces between lab on a chip platform and the bio recognition
element modified with the addition of metal nanoparticle, magnetic beads. During the
last year the research terminated with final testing and comparison system.
Description
Keywords
Chip electrochemical immunosensor , Polycyclic aromatic hydrocarbons , PAHs , Environmental of water , Development of a lab , Environmental pollutants
Citation
Felemban, S. J. 2020. Development of a lab on a chip electrochemical immunosensor array for the detection of polycyclic aromatic hydrocarbons (PAHs) in environmental of water. PhD Thesis, University College Cork.