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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

Schematic of LFA.
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f5-sensors-12-10713: Schematic of LFA.

Mentions: In LFA (Figure 5), there are two lines in the strip, one with antibodies to the target (e.g., anti-E. coli), the other with antibodies to antibody (anti-IgG). Once the sample solution (which may contain target, e.g., E. coli) is applied to the inlet, the anti-E. coli-gold nanoparticle (pre-loaded within the strip) may or may not bind to the target E. coli. The liquid travels through the membrane by capillary action. When the liquid hits the test line, the E. coli + anti-E. coli-gold nanoparticle complex is captured there. The unbound, excess anti-E. coli-gold nanoparticle continues to travel to the control line, which are eventually captured there. Gold nanoparticles absorb green light and some of blue light, so it looks pink. Therefore, two pink bands indicates the presence of target, one band the non-presence of target and no band the failure of assay (mostly because of not enough sample volume to achieve capillary action). Although gold nanoparticles (typically <40 nm [28]) are most frequently used in LFAs, colored or fluorescent latex particles (typically 100–900 nm [29]) are sometimes used.


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

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

Schematic of LFA.
© Copyright Policy
Related In: Results  -  Collection

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

f5-sensors-12-10713: Schematic of LFA.
Mentions: In LFA (Figure 5), there are two lines in the strip, one with antibodies to the target (e.g., anti-E. coli), the other with antibodies to antibody (anti-IgG). Once the sample solution (which may contain target, e.g., E. coli) is applied to the inlet, the anti-E. coli-gold nanoparticle (pre-loaded within the strip) may or may not bind to the target E. coli. The liquid travels through the membrane by capillary action. When the liquid hits the test line, the E. coli + anti-E. coli-gold nanoparticle complex is captured there. The unbound, excess anti-E. coli-gold nanoparticle continues to travel to the control line, which are eventually captured there. Gold nanoparticles absorb green light and some of blue light, so it looks pink. Therefore, two pink bands indicates the presence of target, one band the non-presence of target and no band the failure of assay (mostly because of not enough sample volume to achieve capillary action). Although gold nanoparticles (typically <40 nm [28]) are most frequently used in LFAs, colored or fluorescent latex particles (typically 100–900 nm [29]) are sometimes used.

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