Cardiovascular disease (CVD) is the leading cause of death worldwide. More
than 85% of CVD-related deaths are due to acute myocardial infarction (AMI), which
is more commonly known as heart attack. Affordable and early diagnosis of AMI has
the potential to save millions of lives each year; unfortunately, conventional methods
are ineffective for early diagnosis due to their poor sensitivity. Highly sensitive and
accurate analytical tools to measure cardiac biomarkers are demanded in hospitals for
rapid AMI screening. This dissertation aims to develop cardiac biosensors with the aid
of functional nanomaterials. Porous carbon nitride (PCN), an updated version of
graphitic carbon nitride (GCN) and its functional derivatives, was designed,
synthesized, characterized, and used to fabricate electrochemical aptasensors and field
effect transistor (FET) aptasensors for cardiac biomarkers.
The first part of this dissertation introduces the fabrication and characterization
of laser-scribed graphene (LSG) and the effects of deposition of PCN nanosheet
materials on LSG surfaces. The properties of PCN were further improved through
decorating the nanosheet materials with metal nanoparticles. Moreover, a point-of-care
platform, called KAUSTat, was created by integrating the LSG biosensor with a
custom-made potentiostat and smartphone application. This device demonstrated
exceptional diagnostic potential for usage in hospitals and resource-limited locations
by replacing expensive medical apparatus with simple and practical smart systems,
which could aid in the early diagnosis of AMI. The second part of this dissertation includes the fabrication and characterization
of amorphous indium gallium zinc oxide (IGZO) and PCN materials using
semiconducting metal-oxide bio-FET as a cardiac biosensor for the for the rapid
detection of cardiac biomarkers. The IGZO bio-FET surface was engineered based on
PCN for successful immobilization of the recognition aptamers. We demonstrate a
transistor-based biosensor that paves the way for a rapid and inexpensive detection of
biomarkers. In contrast to existing FET biosensors, which have low sensitivity and
struggle to work with biological samples, the developed Bio-FET sensors exhibited
good selectivity and sensitivity for low concentrations of the cardiac biomarker. The
biosensor holds potential for the rapid, sensitive diagnosis of AMI.
| Date of Award | May 2023 |
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| Original language | English (US) |
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| Awarding Institution | - Biological, Environmental Sciences and Engineering
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| Supervisor | Khaled Salama (Supervisor) |
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