The stability of textile substrate biosensors under artificial saliva and protein solution conditions

Abstract

Biosensors are analytical devices that measure biological or chemical reactions by means of a signal generated in proportion to the concentration of the analyte in the reaction. There are advances being made in the state-of-the-art of detecting blood-based biomarkers for Alzheimer’s Disease (AD), but these require blood which is invasive to collect. The objective of this thesis was to investigate the feasibility of making a fabric-based biosensor that could use saliva as the biofluid input. The made biosensors were tested for their stability when different coatings of Graphene Oxide (GO), reduced Graphene Oxide (rGO), AntiTau-GO, and AntiTau-rGO were added to the textile sensor surfaces. The biosensors were then tested for stability under different conditions of water, phosphate buffered saline, artificial saliva, and biomarker proteins of AD: Amyloid-beta (Aβ) and Tau. The motivation for this thesis is to contribute to the growing field in diagnostic biosensors for AD by testing the feasibility of a textile-based biosensor, and testing its stability under artificial saliva and AD biomarker conditions, respectively. The aim was to contribute to the area of research in biomarker detection for AD as it could test the feasibility of making a point-of-care device, which, in the future, could give a quick response diagnostic test result. Point-of-care (POC) devices provide a rapid acquisition of a diagnostic test result in real-time. With further research development in the future, investigating a non-invasive biosensor, which utilizes a saliva collection method to provide early diagnosis of AD is something that could be tested as a further feasibility study. The results showed promising results for the GO and rGO sensors in the area of repeatability and consistency of the results when solutions were dropped onto the sensors’ surface. The results of the AntiTau-rGO coated sensor showed that the rGO proved to be more selective to the presence of the Tau protein when compared to sensors which did not have the Antibody coating. The thesis contributes to research on AD biomarkers as it showed that future possibilities could be developed, such as point-of-care tests on a fabric substrate, which could be integrated into a wearable device. Developing this could streamline the diagnosis pathway, allow more effective treatment pathways for patients, and provide better care options in the future.

Date of Award	8 Apr 2025
Original language	English
Awarding Institution	The University of Manchester
Supervisor	Alex Casson (Main Supervisor) & Christopher Blanford (Co Supervisor)