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Gold nanoparticle-labeled biosensor for rapid and sensitive detection of bacterial pathogens.

Wang Y, Alocilja EC - J Biol Eng (2015)

Bottom Line: By measuring the amount of AuNPs through an electrochemical method, the presence and the amount of the target bacteria were determined.Results showed a sensitivity of 10(1) colony forming units per milliliter (cfu/ml) with a linear range of 10(1)-10(6) cfu/ml.Compared to conventional culture plating methods, the biosensor reduced the detection time from 2 to 4 days to less than 1 hour with a simple target extraction method.

View Article: PubMed Central - PubMed

Affiliation: Department of Biosystems and Agricultural Engineering, Michigan State University, East Lansing, MI 48824 USA ; Present address: Division of Food Processing Science and Technology, U. S. Food and Drug Administration, Bedford Park, IL 60501 USA.

ABSTRACT

Background: Escherichia coli O157:H7 is one of the major foodborne bacterial pathogens and also a biodefense agent. To ensure food safety and public health, it is very important to develop rapid methods for E. coli O157:H7 detection. In this study, we designed a nanoparticle-labeled biosensor for the rapid detection of E. coli O157:H7 in broth.

Results: Magnetic nanoparticles (MNPs) were conjugated with monoclonal antibodies (Abs) to separate target E. coli O157:H7 cells from broth samples. Gold nanoparticles (AuNPs) were conjugated with polyclonal Abs, and were then introduced to the MNP-target complex to form a sandwich MNP-target-AuNP. By measuring the amount of AuNPs through an electrochemical method, the presence and the amount of the target bacteria were determined. Results showed a sensitivity of 10(1) colony forming units per milliliter (cfu/ml) with a linear range of 10(1)-10(6) cfu/ml.

Conclusions: Compared to conventional culture plating methods, the biosensor reduced the detection time from 2 to 4 days to less than 1 hour with a simple target extraction method. The AuNP-labeled biosensor has potential applications in the rapid detection of infectious agents for public health, biodefense, and food/water safety.

No MeSH data available.


Related in: MedlinePlus

Polyaniline (PANI)-coated magnetic nanoparticles (MNPs). Transmission electron microscopy (TEM) images of: (a) Fe2O3 core; (b) PANI-coated MNPs. The insets show the electron diffraction patterns of the nanoparticles [18]. Used with permission from Biosensors & Bioelectronics
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Fig2: Polyaniline (PANI)-coated magnetic nanoparticles (MNPs). Transmission electron microscopy (TEM) images of: (a) Fe2O3 core; (b) PANI-coated MNPs. The insets show the electron diffraction patterns of the nanoparticles [18]. Used with permission from Biosensors & Bioelectronics

Mentions: E. coli O157:H7 cells were magnetically captured as shown in Fig. 1. We modified the Fe2O3 nanoparticles with polyaniline (PANI) for direct immobilization of anti-E. coli O157:H7 antibody (Ab). Figure 2 presents the transmission electron microscopy (TEM) images of the Fe2O3 nanoparticle core (Fig. 2a) and the PANI-coated MNPs (Fig. 2b) [18]. Figure 2a reveals that the average diameter of the Fe2O3 nanoparticle core is 20 nm, while Fig. 2b shows that the PANI-coated MNPs have diameters ranging from 50 to 100 nm. The increase of the diameter was due to the formation of PANI around the Fe2O3 core. According to the insets, the electron diffraction pattern in Fig. 2a exhibited a typical maghemite (γ-Fe2O3) nanoparticle structure [19]. In Fig. 2b, the electron diffraction pattern shows a set of rings which are typical for PANI [20], noted that it has less bright spots than in Fig. 2a. This pattern also indicates the coating of Fe2O3 core by PANI.Fig. 1


Gold nanoparticle-labeled biosensor for rapid and sensitive detection of bacterial pathogens.

Wang Y, Alocilja EC - J Biol Eng (2015)

Polyaniline (PANI)-coated magnetic nanoparticles (MNPs). Transmission electron microscopy (TEM) images of: (a) Fe2O3 core; (b) PANI-coated MNPs. The insets show the electron diffraction patterns of the nanoparticles [18]. Used with permission from Biosensors & Bioelectronics
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4591638&req=5

Fig2: Polyaniline (PANI)-coated magnetic nanoparticles (MNPs). Transmission electron microscopy (TEM) images of: (a) Fe2O3 core; (b) PANI-coated MNPs. The insets show the electron diffraction patterns of the nanoparticles [18]. Used with permission from Biosensors & Bioelectronics
Mentions: E. coli O157:H7 cells were magnetically captured as shown in Fig. 1. We modified the Fe2O3 nanoparticles with polyaniline (PANI) for direct immobilization of anti-E. coli O157:H7 antibody (Ab). Figure 2 presents the transmission electron microscopy (TEM) images of the Fe2O3 nanoparticle core (Fig. 2a) and the PANI-coated MNPs (Fig. 2b) [18]. Figure 2a reveals that the average diameter of the Fe2O3 nanoparticle core is 20 nm, while Fig. 2b shows that the PANI-coated MNPs have diameters ranging from 50 to 100 nm. The increase of the diameter was due to the formation of PANI around the Fe2O3 core. According to the insets, the electron diffraction pattern in Fig. 2a exhibited a typical maghemite (γ-Fe2O3) nanoparticle structure [19]. In Fig. 2b, the electron diffraction pattern shows a set of rings which are typical for PANI [20], noted that it has less bright spots than in Fig. 2a. This pattern also indicates the coating of Fe2O3 core by PANI.Fig. 1

Bottom Line: By measuring the amount of AuNPs through an electrochemical method, the presence and the amount of the target bacteria were determined.Results showed a sensitivity of 10(1) colony forming units per milliliter (cfu/ml) with a linear range of 10(1)-10(6) cfu/ml.Compared to conventional culture plating methods, the biosensor reduced the detection time from 2 to 4 days to less than 1 hour with a simple target extraction method.

View Article: PubMed Central - PubMed

Affiliation: Department of Biosystems and Agricultural Engineering, Michigan State University, East Lansing, MI 48824 USA ; Present address: Division of Food Processing Science and Technology, U. S. Food and Drug Administration, Bedford Park, IL 60501 USA.

ABSTRACT

Background: Escherichia coli O157:H7 is one of the major foodborne bacterial pathogens and also a biodefense agent. To ensure food safety and public health, it is very important to develop rapid methods for E. coli O157:H7 detection. In this study, we designed a nanoparticle-labeled biosensor for the rapid detection of E. coli O157:H7 in broth.

Results: Magnetic nanoparticles (MNPs) were conjugated with monoclonal antibodies (Abs) to separate target E. coli O157:H7 cells from broth samples. Gold nanoparticles (AuNPs) were conjugated with polyclonal Abs, and were then introduced to the MNP-target complex to form a sandwich MNP-target-AuNP. By measuring the amount of AuNPs through an electrochemical method, the presence and the amount of the target bacteria were determined. Results showed a sensitivity of 10(1) colony forming units per milliliter (cfu/ml) with a linear range of 10(1)-10(6) cfu/ml.

Conclusions: Compared to conventional culture plating methods, the biosensor reduced the detection time from 2 to 4 days to less than 1 hour with a simple target extraction method. The AuNP-labeled biosensor has potential applications in the rapid detection of infectious agents for public health, biodefense, and food/water safety.

No MeSH data available.


Related in: MedlinePlus