While the Canadian food supply is among the healthiest in the world, almost 4 million (1
in 8) Canadians are affected by food-borne illnesses, resulting in 11,600 hospitalizations
and 238 deaths per year. Microbial pathogens are one of the major causes of foodborne
sicknesses that can grow in food before or following packaging. Food distribution is an
important part of the food processing chain, in which food supplies are at a higher risk of
contamination due to lack of proper monitoring. Among myriad of research around
biosensors, current devices focusing on packaged food monitoring, such as leakage
indicators or time temperature sensors are not efficient for real-time food monitoring
without separating the sample from the stock. Packaged food such as meat and juice are
directly in touch with the surface of their containers or covers. Therefore, real-time sensing
mechanisms, installed inside the food packaging and capable of tracing the presence of
pathogens, are of great interest to ensure food safety. This work involves developing thin,
transparent, flexible and durable sensing surfaces using DNA biosensors, which report the
presence of a target bacterium in food or water samples by generating a fluorescence signal
that can be detected by simple fluorescence detecting devices. The covalently-attached
DNA probes generate the signal upon contact with the target bacteria with as low as 103
CFU/mL of Escherichia coli in meat and apple juice. The fabricated sensing surfaces
remained stable up to several days under varying pH conditions (pH 5 to 9). In addition to
detecting pathogens on packaged food or drinking bottles, these surfaces have the potential
to be used for a variety of other applications in health care settings, environmental
monitoring, food production chain, and biomaterials like wound dressing. / Thesis / Master of Science (MSc) / Microbial pathogens can grow in food following packaging and preceding consumption.
Current biosensors are not efficient for post-packaging real-time food monitoring without
separating the sample from the stock. Packaged food such as meat and juice are directly in
touch with the surface of their containers or covers. Therefore, real-time sensing
mechanisms, installed inside the food packaging, tracing the presence of pathogens, are
much useful to ensure the food safety. Here we report on developing thin, transparent,
flexible and durable sensing surfaces using DNA biosensors, which generate a fluorescence
signal in the presence of a target bacterium in food or water samples. The covalentlyattached
DNA probes can detect as low as 103 CFU/mL of Escherichia coli in meat, sliced
apple and apple juice. The fabricated sensing surfaces remained stable up to several days
under varying pH conditions (pH 5 to 9). In addition to pathogen monitoring in packaged
food or drinking bottles, these surfaces are promising for a variety of other applications in
health care settings, environmental monitoring, and biomaterials like wound dressing.
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/22127 |
| Date | 11 1900 |
| Creators | Yousefi, Hanie |
| Contributors | D. M. Filipe, Carlos, F. Didar, Tohid, Chemical Engineering |
| Source Sets | McMaster University |
| Language | English |
| Detected Language | English |
| Type | Thesis |
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