Development of a novel epitope-imprinted polydopamine interface for food allergen recognition | |
| Author | Tabkrich Khumsap |
| Call Number | AIT Diss no.FB-22-01 |
| Subject(s) | Food allergy Imprinted polymers |
| Note | A dissertation submitted in partial fulfillment of the requirements for the degree of doctor of Philosophy in Food Engineering and Bioprocess Technology |
| Publisher | Asian Institute of Technology |
| Abstract | Food allergy represents a global public health concern with increasing prevalence. Besides strict measures to prevent the unwanted contact with allergenic ingredients, detection of allergens in the food supply chain is imperative to protect hypersensitive consumers. Generally, food allergens are proteins which can be recognized by corresponding antibodies or aptamers. However, the applicability of these biological receptors is restricted by their high cost and low stability. Recently, molecularly imprinted polymers (MIPs) have been considered as a dependable tool for protein recognition. However, molecular imprinting of the whole protein molecule is complicated by its large size, conformational instability, and structural complexity. These inherent limitations can be overcome by epitope imprinting approach. In this work, the synthesis and applications of allergen-specific epitope-imprinted polymers (EIPs) were investigated. Egg ovalbumin (OVA), one of the most popular allergenic proteins, was employed to demonstrate proof-of-concept. First, molecular docking was used to screen the appropriate epitope template and monomer for the synthesis of EIP with affinity to OVA. It was found that EDTQAMPFRV-dopamine complex had the highest docking score and was the most suitable for the imprinting process. Second, epitope-imprinted polydopamine magnetic nanoparticles (EIP-MNPs) were developed for selective separation of OVA from food matrix. The obtained EIP-MNPs had high affinity to OVA with an imprinting factor (IF) of 7.52. EIP-MNPs also exhibited good selectivity against selected interferents. The recovery percentage of OVA from real food samples ranged from 95.4% to 105.7%, with the RSD from 3.3% to 5.7%. Third, epitope-imprinted polydopamine was further grafted onto a screen printed electrode for electrochemical detection of OVA. The sensor demonstrated excellent sensitivity toward OVA with limit of detection (LOD) of 10.76 nM (0.46 ppm), and limit of quantification (LOQ) of 35.87 nM (1.54 ppm). When tested with real food samples, the sensor performance was found to be satisfactory with RSD of 5.6-10.8%, and recovery percentage of 104.7-106.0%. Finally, EIP-based sensors were applied for multiplex detection of allergens in a programmable pressure-driven flow system. The sensors installed in the system was able to detect the spiked allergens with selectivity and sensitivity satisfying the regulated standards. Throughout this study, with facile synthesis and propitious applications, EIPs have demonstrated to be a promising platform for the analysis of allergens in the future. |
| Year | 2022 |
| Type | Dissertation |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Food, Agriculture and Natural Resources (Former title: Department of Food Agriculture, and BioResources (DFAB)) |
| Academic Program/FoS | Food Engineering and Bioprocess Technology (FB) |
| Chairperson(s) | Loc Thai Nguyen |
| Examination Committee(s) | Anal, Anil Kumar;Attaphongse Taparugssanagorn |
| Scholarship Donor(s) | Royal Thai Government Fellowship;Asian Institute of Technology Fellowship |
| Degree | Thesis (Ph.D.) - Asian Institute of Technology, 2022 |