Early-onset diagnostics, or the detection of disease before clinical symptoms arise, has
gained traction for its potential to improve patient quality of life and health outcomes.
Biosensors, found in point-of-care (POC) devices, facilitate early-onset diagnostics and
disease monitoring by addressing the limitations of current diagnostics strategies, which
include timeliness, cost-effectiveness, and accessibility. Biosensors often incorporate
microarrays within their design to allow for the detection of disease-associated
biomolecules, known as biomarkers. Microarrays are composed of capture biomolecules,
such as monoclonal antibodies, that are immobilized through either contact or non-contact
printing techniques. In the following thesis, we investigated microarray designs within
novel biosensing platforms for diagnostic and disease monitoring applications. First, we
highlighted the advantages and challenges of implementing different types of biosensors,
detection methods, and biomolecule immobilization strategies. Additionally, we proposed
a novel 3D microarray incorporating hydrogels composed purely of crosslinked bovine
serum albumin (BSA) proteins decorated with capture antibodies (CAbs). Utilizing
industry-standard inkjet printing, we developed and optimized a two-step fabrication
protocol, by which BSA proteins and CAbs are printed first, followed by the crosslinking
agent, 1-Ethyl-3-[3-dimethylaminopropyl]carbodiimide (EDC). Characterization of the
unique three-dimensional (3D) microstructure and hydrogel parameters and conducting
comparisons with standard two-dimensional (2D) microdots, showed that increasing
biosensor surface area led to a 3X increase in signal amplification. The limits of detection
(LODs) for cytokine biomarkers were 0.3pg/mL for interleukin-6 (IL-6) and 1pg/mL for tumor necrosis factor receptor I (TNF RI), which were highly sensitive compared to
reported LODs from literature. Alongside the investigation of novel printing protocols,
proof-of-concepts for multiplex detection and distinguishing clinical patient samples from
healthy donors were also presented. Overall, this thesis demonstrated the fabrication and
optimization of microarray development shows promise in improving current biosensor
designs, allowing for enhanced early-onset disease detection and monitoring. / Thesis / Master of Applied Science (MASc)
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/29086 |
| Date | January 2023 |
| Creators | Najm, Lubna |
| Contributors | Didar, Tohid, Biomedical Engineering |
| Source Sets | McMaster University |
| Language | English |
| Detected Language | English |
| Type | Thesis |
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