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Electrochemical biosensor for rapid and sensitive detection of magnetically extracted bacterial pathogens.

Setterington EB, Alocilja EC - Biosensors (Basel) (2012)

Bottom Line: Cyclic voltammetry is combined with immunomagnetic separation in a rapid method requiring approximately 1 h for presumptive positive/negative results.The presence of target cells significantly inhibits current flow between the electrically active c/sNPs and SPCE.This method has the potential to be adapted for a wide variety of target organisms and sample matrices, and to become a fully portable system for routine monitoring or emergency detection of bacterial pathogens.

View Article: PubMed Central - PubMed

Affiliation: Department of Biosystems and Agricultural Engineering, Michigan State University, East Lansing, MI 48824, USA. ebs@msu.edu.

ABSTRACT
Biological defense and security applications demand rapid, sensitive detection of bacterial pathogens. This work presents a novel qualitative electrochemical detection technique which is applied to two representative bacterial pathogens, Bacillus cereus (as a surrogate for B. anthracis) and Escherichia coli O157:H7, resulting in detection limits of 40 CFU/mL and 6 CFU/mL, respectively, from pure culture. Cyclic voltammetry is combined with immunomagnetic separation in a rapid method requiring approximately 1 h for presumptive positive/negative results. An immunofunctionalized magnetic/polyaniline core/shell nano-particle (c/sNP) is employed to extract target cells from the sample solution and magnetically position them on a screen-printed carbon electrode (SPCE) sensor. The presence of target cells significantly inhibits current flow between the electrically active c/sNPs and SPCE. This method has the potential to be adapted for a wide variety of target organisms and sample matrices, and to become a fully portable system for routine monitoring or emergency detection of bacterial pathogens.

No MeSH data available.


Related in: MedlinePlus

Cyclic voltammograms of immuno-c/sNP-cell solutions: (a) B. cereus cell concentrations ranging from 4 to 3.9 × 102 CFU/mL; and (b) E. coli O157:H7 cell concentrations ranging from 6 CFU/mL to 5.9 × 104 CFU/mL.
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biosensors-02-00015-f005: Cyclic voltammograms of immuno-c/sNP-cell solutions: (a) B. cereus cell concentrations ranging from 4 to 3.9 × 102 CFU/mL; and (b) E. coli O157:H7 cell concentrations ranging from 6 CFU/mL to 5.9 × 104 CFU/mL.

Mentions: Electrochemical tests were performed on immuno-c/sNP-cell solutions with various concentrations of B. cereus and E. coli O157:H7 cells. The concentration of c/sNPs was constant at 1 mg/mL. In all cases, the polyaniline shell of the c/sNPs had been doped prior to testing by incubation in 0.1 M HCl. Figure 5 shows the cyclic voltammograms for (a) B. cereus and (b) E. coli O157:H7, comparing blank tests (no cells) to cell concentrations ranging from 100 to 102 (B. cereus) or 104 (E. coli O157:H7) CFU/mL. It is evident that the current response decreases with an increasing number of cells present on the sensor, as expected. The only exception to this is at the two highest concentrations of E. coli O157:H7, 5.9 × 103 and 5.9 × 104 CFU/mL, which actually result in a current response much larger than that of the blank test.


Electrochemical biosensor for rapid and sensitive detection of magnetically extracted bacterial pathogens.

Setterington EB, Alocilja EC - Biosensors (Basel) (2012)

Cyclic voltammograms of immuno-c/sNP-cell solutions: (a) B. cereus cell concentrations ranging from 4 to 3.9 × 102 CFU/mL; and (b) E. coli O157:H7 cell concentrations ranging from 6 CFU/mL to 5.9 × 104 CFU/mL.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4263547&req=5

biosensors-02-00015-f005: Cyclic voltammograms of immuno-c/sNP-cell solutions: (a) B. cereus cell concentrations ranging from 4 to 3.9 × 102 CFU/mL; and (b) E. coli O157:H7 cell concentrations ranging from 6 CFU/mL to 5.9 × 104 CFU/mL.
Mentions: Electrochemical tests were performed on immuno-c/sNP-cell solutions with various concentrations of B. cereus and E. coli O157:H7 cells. The concentration of c/sNPs was constant at 1 mg/mL. In all cases, the polyaniline shell of the c/sNPs had been doped prior to testing by incubation in 0.1 M HCl. Figure 5 shows the cyclic voltammograms for (a) B. cereus and (b) E. coli O157:H7, comparing blank tests (no cells) to cell concentrations ranging from 100 to 102 (B. cereus) or 104 (E. coli O157:H7) CFU/mL. It is evident that the current response decreases with an increasing number of cells present on the sensor, as expected. The only exception to this is at the two highest concentrations of E. coli O157:H7, 5.9 × 103 and 5.9 × 104 CFU/mL, which actually result in a current response much larger than that of the blank test.

Bottom Line: Cyclic voltammetry is combined with immunomagnetic separation in a rapid method requiring approximately 1 h for presumptive positive/negative results.The presence of target cells significantly inhibits current flow between the electrically active c/sNPs and SPCE.This method has the potential to be adapted for a wide variety of target organisms and sample matrices, and to become a fully portable system for routine monitoring or emergency detection of bacterial pathogens.

View Article: PubMed Central - PubMed

Affiliation: Department of Biosystems and Agricultural Engineering, Michigan State University, East Lansing, MI 48824, USA. ebs@msu.edu.

ABSTRACT
Biological defense and security applications demand rapid, sensitive detection of bacterial pathogens. This work presents a novel qualitative electrochemical detection technique which is applied to two representative bacterial pathogens, Bacillus cereus (as a surrogate for B. anthracis) and Escherichia coli O157:H7, resulting in detection limits of 40 CFU/mL and 6 CFU/mL, respectively, from pure culture. Cyclic voltammetry is combined with immunomagnetic separation in a rapid method requiring approximately 1 h for presumptive positive/negative results. An immunofunctionalized magnetic/polyaniline core/shell nano-particle (c/sNP) is employed to extract target cells from the sample solution and magnetically position them on a screen-printed carbon electrode (SPCE) sensor. The presence of target cells significantly inhibits current flow between the electrically active c/sNPs and SPCE. This method has the potential to be adapted for a wide variety of target organisms and sample matrices, and to become a fully portable system for routine monitoring or emergency detection of bacterial pathogens.

No MeSH data available.


Related in: MedlinePlus