{"id":194,"date":"2020-11-02T03:43:04","date_gmt":"2020-11-02T08:43:04","guid":{"rendered":"https:\/\/www.cd-bioparticles.com\/blog\/?p=194"},"modified":"2020-11-02T03:43:04","modified_gmt":"2020-11-02T08:43:04","slug":"just-one-click-to-detect-escherichia-coli","status":"publish","type":"post","link":"https:\/\/www.cd-bioparticles.com\/blog\/magnetic-beads\/just-one-click-to-detect-escherichia-coli\/","title":{"rendered":"Just One Click to Detect Escherichia coli"},"content":{"rendered":"\n
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With the rapid\ndevelopment of the food industry and the change of consumers’ consumption\nhabits, the requirements for food hygiene and food safety are getting higher\nand higher. Due to the influence of environment and climate, the probability of\nfood diseases caused by foodborne pathogens is getting higher and higher. The\nWorld Health Organization (WHO) pointed out that foodborne pathogens are the\nmain food safety risks, which can cause foodborne diseases and food poisoning\noutbreaks. Statistics show that there are more than 200 million cases of\nfoodborne diarrhea worldwide every year, and more than 65% of people in these\ncases have eaten food contaminated by foodborne pathogens.<\/p>\n\n\n\n

Conventional\ntechniques<\/p>\n\n\n\n

The\nconventional identification method of pathogenic bacteria mainly refers to the\nmethod of observation and culture. Although culture method is sensitive, cheap,\nand can provide qualitative and quantitative information about the quantity and\nproperties of microorganisms in food samples, it has the disadvantage of\ntime-consuming.<\/p>\n\n\n\n

Rapid\ndetection techniques<\/p>\n\n\n\n

Rapid\ndetection techniques are developed on the basis of conventional methods, which\nhas the advantages of time-saving, simple operation, and high accuracy (Table\n1).<\/p>\n\n\n\n

Table 1. Rapid techniques for the detection of foodborne pathogens.<\/p>\n\n\n\n

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Because\nthe immunomagnetic separation method has a fast and simple pretreatment process\nfor on-site purification of pathogenic bacteria, it has been widely used. It\nuses antibody-conjugated magnetic nanoparticles (MNPs) to react with bacteria\nunder the action of a magnetic field to separate target bacteria from the food\nmatrix. Immunomagnetic separation can simply separate bacteria from the food\nmatrix, but when free MNP coexists during the process of bacterial isolation,\nthe use of immunomagnetic separation often causes analytical errors.<\/p>\n\n\n\n

Professor\nPark said \u201cthese methods require laborious equipment to read out the result\nsignal or to separate unbound free MNPs, so that they are insufficient for the\non-site detection method.\u201d<\/p>\n\n\n\n

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Figure 1. Schematic of the device. <\/figcaption><\/figure><\/div>\n\n\n\n

Therefore,\nJo et al. studied a finger-powered microfluidic device to quickly detect E.\ncoli<\/em> O157:H7 on site (Figure 1, full results found on Sensors<\/em>). In order to separate free MNP and detect the E. coli<\/em>\nO157:H7 bound to MNPs by colorimetric signals, they integrated a membrane\nfilter into the finger-powered microfluidic device. With the activation button,\nthe reagent is distributed to the filter area, and the unbound free MNPs are\nremoved by the absorbent under the membrane filter. When using gold-coated\nMNPs, the colorimetric signal of filtered MNPs bound to E. coli<\/em> O157:H7\nis amplified by injecting a gold enhancer solution.<\/p>\n\n\n\n

In this article, Jo et al.<\/em> uses carboxyl functionalized MNPs (purchased from CD Bioparticles) to capture E. coli<\/em> O157:H7, and uses the colorimetric signal amplified by a finger-powered microfluidic device integrated with a membrane filter to detect it. After immunomagnetic separation, by simply pressing and releasing the pressure chamber, the mixture of MNP-binding bacteria and free MNPs can be loaded onto the membrane filter of the device. By optimizing the pore size of the membrane filter and the incubation time of the gold enhancer, at least 102<\/sup> CFU\/mL of E. coli<\/em> O157:H7 can be detected within 1 h. Professor Park said, “Although the detection limit is not as low as other studies based on fluorescence or SERS signals, it is worth mentioning that the device does not require other external signal readers or external pumping systems. By integrating the device into the immunomagnetic separation device, it is expected to play an important role in the on-site detection of foodborne pathogens.”<\/p>\n\n\n\n

Reference:
Jo, Y., Park, J., & Park, J. K. (2020). Colorimetric Detection of Escherichia coli O157: H7 with Signal Enhancement Using Size-Based Filtration on a Finger-Powered Microfluidic Device. Sensors<\/em>, 20(8), 2267. <\/p><\/blockquote>\n","protected":false},"excerpt":{"rendered":"

With the rapid development of the food industry and the change of consumers’ consumption habits, the requirements for food hygiene<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7,6],"tags":[51,4,47],"class_list":["post-194","post","type-post","status-publish","format-standard","hentry","category-applications","category-magnetic-beads","tag-e-coli","tag-magnetic-particles","tag-microfluidic-technology"],"_links":{"self":[{"href":"https:\/\/www.cd-bioparticles.com\/blog\/wp-json\/wp\/v2\/posts\/194","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.cd-bioparticles.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.cd-bioparticles.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.cd-bioparticles.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.cd-bioparticles.com\/blog\/wp-json\/wp\/v2\/comments?post=194"}],"version-history":[{"count":1,"href":"https:\/\/www.cd-bioparticles.com\/blog\/wp-json\/wp\/v2\/posts\/194\/revisions"}],"predecessor-version":[{"id":198,"href":"https:\/\/www.cd-bioparticles.com\/blog\/wp-json\/wp\/v2\/posts\/194\/revisions\/198"}],"wp:attachment":[{"href":"https:\/\/www.cd-bioparticles.com\/blog\/wp-json\/wp\/v2\/media?parent=194"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.cd-bioparticles.com\/blog\/wp-json\/wp\/v2\/categories?post=194"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.cd-bioparticles.com\/blog\/wp-json\/wp\/v2\/tags?post=194"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}