Design and development of a microfluidic integrated electrochemical nanobiosensor for detection of SARS-CoV-2 Nucleocapsid protein biomarker
Date
2021-12-13
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
The rapid spread of infectious disease outbreaks, such as the COVID-19 pandemic, once again emphasized the importance of deploying the potentials of biosensing technologies, as a key tool for controlling further transmission. Although the gold standard technique, Polymerase Chain Reaction (PCR), has become swiftly adopted, their limitations ask for more rapid, time-saving, and miniaturized approaches, such as all-in-one portable diagnostic platforms. Depending on the biosensing approach, the sensing element and the fluid-handling segment are considered as the most important elements of such platforms. As for the sensing methods, electrochemical immunosensing proved to have the sensitivity required for detecting the low amount of target proteins, which is favorable for early-disease detection, only if the surface of the sensor is modified to exhibit a high capacity for specific probe immobilization. Hence, introducing highly receptive surfaces is important for enhancing the sensitivity. For utilizing electrochemical immunosensors in point-of-care devices, the challenge of accommodating all of the conventionally lab-centralized sensing processes into one single chip also requires further research and investigation. To this end, the focus of the present thesis was to introduce an ultrasensitive nano-biosensor based on Zinc Oxide (ZnO) and Reduced Graphene Oxide (rGO) nanocomponents, which could successfully create a highly porous and stable sensing surface. The coated electrodes were functionalized with an L-cysteine cross-linker to provide abundant sources of carboxylic acid functional groups, an essential moiety for antibody immobilization. The morphology, physical and chemical characteristics of the sensing surface were thoroughly analyzed using spectroscopy and microscopy techniques. The electrochemical impedance spectroscopy (EIS) experiments confirmed the functionality of the immunosensor for detecting as low as 21 fg/mL SARS-CoV-2 biomarker, the Nucleocapsid (N-) protein, while it was further used for clinically detecting positive clinical swab samples. The integration of the biosensor into a microfluidic testing kit was also been explored, with a novel redox-contained chip automating all steps of immunosensing in one single kit. The platform successfully operated within 15 min for detecting N-proteins of the nasopharyngeal (NP) swab sample. This electrochemical biosensor integrated within the accompanying microfluidic chip provides a promising perspective towards the realization of a point-of-care platform.
Description
Keywords
Microfluidic Platforms, Electrochemical Biosensors
Citation
Haghayegh, F. (2021). Design and development of a microfluidic integrated electrochemical nanobiosensor for detection of SARS-CoV-2 Nucleocapsid protein biomarker (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.