Development of electrochemical and optical bioassays for food analysis and human health

• Main Author: Lim, Rachel Rui Xia
• Other Authors: Alessandra Bonanni
• Format: Thesis-Doctor of Philosophy
• Language: English
• Published: Nanyang Technological University 2024
• Subjects: Chemistry
• Online Access: https://hdl.handle.net/10356/177862
• Institution: Nanyang Technological University

Recent studies have reported on the influences of genetically modified organisms (GMO) and some gut-derived metabolites from food on health, diseases and aging. However, the current detection methods for GMO screening and gut-derived metabolites are costly, time-intensive, as well as involve trained personnel and bulky equipment during operation. Hence, my PhD research aims to overcome these challenges by developing economical, rapid, highly sensitive, selective as well as portable electrochemical and optical bioassays to detect these analytes-of-interest with the help of some promising nanomaterials under Group 14 of the periodic table. In the 1st chapter of my thesis, working principles of different electrochemical and optical methods will be first introduced, followed by some examples of bioassays based on their biorecognition elements that we can capitalize on in the applications for food analysis and human health. For the 2nd chapter of my thesis, we explored the use of various electroactive nanocarbon materials as electrochemical tags for the detection of GMO amplicon by electrochemical polymerase chain reaction. Next, in the 3rd chapter of my thesis, we investigated different nanosized germanene-based materials as competitive electrochemical impedimetric immunosensors to detect gut-derived metabolites as biomarkers using screen-printed electrodes. Under the 4th chapter of my thesis, we developed a portable smartphone-assisted graphene quantum dots sensing platform for the detection of gut-derived metabolites where we compared the analytical figures of merits achieved by the smartphone-based method against the fluorescence spectrophotometer. Finally, in the last chapter of my thesis, the future directions of electrochemical and optical bioassays towards food and clinical analyses will be proposed. Ultimately, this research serves to develop promising user-friendly bioassays for on-site food safety monitoring and point-of-care clinical testing, while demonstrating the properties and suitability of Group 14-based nanomaterials for these biosensing purposes.