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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

Continuous-flow PCR on a chip. Reprinted from [80] with permission © American Association for the Advancement of Science.
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f11-sensors-12-10713: Continuous-flow PCR on a chip. Reprinted from [80] with permission © American Association for the Advancement of Science.

Mentions: In conventional PCR, a single tube is repeatedly heated up and cooled down to achieve the desired temperatures. The environment for a tube, such as a Peltier plate, should be fully heated up and cooled down to make the tube to reach at desired temperature. As this process is primarily based on conduction heat transfer, which is the slowest among the three heat transfer mechanisms (conduction, convention and radiation), it often takes a couple of minutes to complete a single cycle (and thus over an hour to finish the typical 20–40 cycles of PCR). In a stationary chamber PCR lab-on-a-chip, the chamber is made very small to shorten this heating and cooling time. A better alternative is to move this liquid over three different temperature areas within lab-on-a-chip, so that the time required for heating and cooling may be significantly reduced, thus leading to a faster PCR assay. The first such demonstration was made by Kopp et al., where a single serpentine microfluidic channel travels through three different temperature zones to achieve 20-cycle PCR. In this manner, <20-min or even <10-min 20–40-cycle PCR has become a possibility. Figure 11 shows the continuous-flow PCR on a chip made by Kopp et al. [79].


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

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

Continuous-flow PCR on a chip. Reprinted from [80] with permission © American Association for the Advancement of Science.
© Copyright Policy
Related In: Results  -  Collection

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

f11-sensors-12-10713: Continuous-flow PCR on a chip. Reprinted from [80] with permission © American Association for the Advancement of Science.
Mentions: In conventional PCR, a single tube is repeatedly heated up and cooled down to achieve the desired temperatures. The environment for a tube, such as a Peltier plate, should be fully heated up and cooled down to make the tube to reach at desired temperature. As this process is primarily based on conduction heat transfer, which is the slowest among the three heat transfer mechanisms (conduction, convention and radiation), it often takes a couple of minutes to complete a single cycle (and thus over an hour to finish the typical 20–40 cycles of PCR). In a stationary chamber PCR lab-on-a-chip, the chamber is made very small to shorten this heating and cooling time. A better alternative is to move this liquid over three different temperature areas within lab-on-a-chip, so that the time required for heating and cooling may be significantly reduced, thus leading to a faster PCR assay. The first such demonstration was made by Kopp et al., where a single serpentine microfluidic channel travels through three different temperature zones to achieve 20-cycle PCR. In this manner, <20-min or even <10-min 20–40-cycle PCR has become a possibility. Figure 11 shows the continuous-flow PCR on a chip made by Kopp et al. [79].

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