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Lab-on-a-chip pathogen sensors for food safety.

Yoon JY, Kim B - Sensors (Basel) (2012)

Bottom Line: Several different types of lab-on-a-chip biosensors, including immunoassay- and PCR-based, have been developed and tested for detecting foodborne pathogens.Their assay performance, including detection limit and assay time, are also summarized.Finally, the use of optical fibers or optical waveguide is discussed as a means to improve the portability and sensitivity of lab-on-a-chip pathogen sensors.

View Article: PubMed Central - PubMed

Affiliation: Department of Agricultural and Biosystems Engineering, the University of Arizona, Tucson, AZ 85721, USA. jyyoon@email.arizona.edu

ABSTRACT
There have been a number of cases of foodborne illness among humans that are caused by pathogens such as Escherichia coli O157:H7, Salmonella typhimurium, etc. The current practices to detect such pathogenic agents are cell culturing, immunoassays, or polymerase chain reactions (PCRs). These methods are essentially laboratory-based methods that are not at all real-time and thus unavailable for early-monitoring of such pathogens. They are also very difficult to implement in the field. Lab-on-a-chip biosensors, however, have a strong potential to be used in the field since they can be miniaturized and automated; they are also potentially fast and very sensitive. These lab-on-a-chip biosensors can detect pathogens in farms, packaging/processing facilities, delivery/distribution systems, and at the consumer level. There are still several issues to be resolved before applying these lab-on-a-chip sensors to field applications, including the pre-treatment of a sample, proper storage of reagents, full integration into a battery-powered system, and demonstration of very high sensitivity, which are addressed in this review article. Several different types of lab-on-a-chip biosensors, including immunoassay- and PCR-based, have been developed and tested for detecting foodborne pathogens. Their assay performance, including detection limit and assay time, are also summarized. Finally, the use of optical fibers or optical waveguide is discussed as a means to improve the portability and sensitivity of lab-on-a-chip pathogen sensors.

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Related in: MedlinePlus

Left: A short sequence of DNA captures a target, complementary sequence, and a subsequent signal is detected in a manner similar to ELISA. Right: The same is demonstrated in a microfluidic channel in a manner similar to ELISA lab-on-a-chip.
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f10-sensors-12-10713: Left: A short sequence of DNA captures a target, complementary sequence, and a subsequent signal is detected in a manner similar to ELISA. Right: The same is demonstrated in a microfluidic channel in a manner similar to ELISA lab-on-a-chip.

Mentions: Immunoassay-based lab-on-a-chips detect the presence of antigens on or from the pathogens. Binding of antibodies to their corresponding antigens are highly specific, but it is not always perfect. Cross-binding is common; for example, anti-E. coli often binds to other similar bacteria, such as Salmonella. A certain sequence of DNA or RNA can be used to detect its complementary sequence from pathogens, just like ELISA and ELISA lab-on-a-chip, where primary and secondary antibodies are replaced with capture and detector probes (short DNA or RNA sequences) (Figure 10). This sandwich DNA assay lab-on-a-chip provides much more specific assay results [69–73].


Lab-on-a-chip pathogen sensors for food safety.

Yoon JY, Kim B - Sensors (Basel) (2012)

Left: A short sequence of DNA captures a target, complementary sequence, and a subsequent signal is detected in a manner similar to ELISA. Right: The same is demonstrated in a microfluidic channel in a manner similar to ELISA lab-on-a-chip.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3472853&req=5

f10-sensors-12-10713: Left: A short sequence of DNA captures a target, complementary sequence, and a subsequent signal is detected in a manner similar to ELISA. Right: The same is demonstrated in a microfluidic channel in a manner similar to ELISA lab-on-a-chip.
Mentions: Immunoassay-based lab-on-a-chips detect the presence of antigens on or from the pathogens. Binding of antibodies to their corresponding antigens are highly specific, but it is not always perfect. Cross-binding is common; for example, anti-E. coli often binds to other similar bacteria, such as Salmonella. A certain sequence of DNA or RNA can be used to detect its complementary sequence from pathogens, just like ELISA and ELISA lab-on-a-chip, where primary and secondary antibodies are replaced with capture and detector probes (short DNA or RNA sequences) (Figure 10). This sandwich DNA assay lab-on-a-chip provides much more specific assay results [69–73].

Bottom Line: Several different types of lab-on-a-chip biosensors, including immunoassay- and PCR-based, have been developed and tested for detecting foodborne pathogens.Their assay performance, including detection limit and assay time, are also summarized.Finally, the use of optical fibers or optical waveguide is discussed as a means to improve the portability and sensitivity of lab-on-a-chip pathogen sensors.

View Article: PubMed Central - PubMed

Affiliation: Department of Agricultural and Biosystems Engineering, the University of Arizona, Tucson, AZ 85721, USA. jyyoon@email.arizona.edu

ABSTRACT
There have been a number of cases of foodborne illness among humans that are caused by pathogens such as Escherichia coli O157:H7, Salmonella typhimurium, etc. The current practices to detect such pathogenic agents are cell culturing, immunoassays, or polymerase chain reactions (PCRs). These methods are essentially laboratory-based methods that are not at all real-time and thus unavailable for early-monitoring of such pathogens. They are also very difficult to implement in the field. Lab-on-a-chip biosensors, however, have a strong potential to be used in the field since they can be miniaturized and automated; they are also potentially fast and very sensitive. These lab-on-a-chip biosensors can detect pathogens in farms, packaging/processing facilities, delivery/distribution systems, and at the consumer level. There are still several issues to be resolved before applying these lab-on-a-chip sensors to field applications, including the pre-treatment of a sample, proper storage of reagents, full integration into a battery-powered system, and demonstration of very high sensitivity, which are addressed in this review article. Several different types of lab-on-a-chip biosensors, including immunoassay- and PCR-based, have been developed and tested for detecting foodborne pathogens. Their assay performance, including detection limit and assay time, are also summarized. Finally, the use of optical fibers or optical waveguide is discussed as a means to improve the portability and sensitivity of lab-on-a-chip pathogen sensors.

Show MeSH
Related in: MedlinePlus