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A Self-Referencing Detection of Microorganisms Using Surface Enhanced Raman Scattering Nanoprobes in a Test-in-a-Tube Platform.

Xiao N, Wang C, Yu C - Biosensors (Basel) (2013)

Bottom Line: Anisotropic nanoparticles (i.e., silver nanocubes) were functionalized with target-specific antibodies and Raman active tags to serve as nanoprobes for the rapid detection of bacteria in a test-in-a-tube platform.The assessment through the dual signals (superimposed target and tag Raman signatures) supported a specific recognition of the targets in a single step with no washing/separation needed to a sensitivity of 102 CFU/mL, even in the presence of non-target bacteria at a 10 times higher concentration.The self-referencing protocol implemented with a portable Raman spectrometer potentially can become an easy-to-use, field-deployable spectroscopic sensor for onsite detection of pathogenic microorganisms.

View Article: PubMed Central - PubMed

Affiliation: Department of Agricultural and Biosystems Engineering, Iowa State University, Ames, IA 50011, USA. nxiao@iastate.edu.

ABSTRACT
Anisotropic nanoparticles (i.e., silver nanocubes) were functionalized with target-specific antibodies and Raman active tags to serve as nanoprobes for the rapid detection of bacteria in a test-in-a-tube platform. A self-referencing scheme was developed and implemented in which surface enhanced Raman spectroscopic (SERS) signatures of the targets were observed superimposed with the SERS signals of the Raman tags. The assessment through the dual signals (superimposed target and tag Raman signatures) supported a specific recognition of the targets in a single step with no washing/separation needed to a sensitivity of 102 CFU/mL, even in the presence of non-target bacteria at a 10 times higher concentration. The self-referencing protocol implemented with a portable Raman spectrometer potentially can become an easy-to-use, field-deployable spectroscopic sensor for onsite detection of pathogenic microorganisms.

No MeSH data available.


Related in: MedlinePlus

SERS spectra of silver nanoprobes with anti-E. coli antibodies interacted with E. coli and Listeria mixture sample solutions with different E. coli:Listeria ratio.
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biosensors-03-00312-f007: SERS spectra of silver nanoprobes with anti-E. coli antibodies interacted with E. coli and Listeria mixture sample solutions with different E. coli:Listeria ratio.

Mentions: The specificity of the self-referencing dual-recognition scheme is determined by the specificity of the antibodies. As illustrated in Figure 7, when a sample with non-targets (L. monocytogenes, 103 CFU/mL) was integrated by the nanoprobes (specifically E. coli), no self-referencing signatures (735 cm–1, 825 cm–1 and 985 cm–1) were observed which resulted in a correct negative I.D. For a sample with a 10-fold higher non-targets (L. monocytogenes, 103 CFU/mL) concentration than target (E. coli, 102 CFU/mL), the specific E. coli peaks could still be identified, as shown in Figure 7. Relatively high level of interferences from other bacteria (L. monocytogenes) did not diminish the accuracy of the self-referencing dual-recognition scheme, indicating that this scheme would be extremely attractive to in-field pathogen detection applications, where interference from other co-existed microorganism species will be omnipresent.


A Self-Referencing Detection of Microorganisms Using Surface Enhanced Raman Scattering Nanoprobes in a Test-in-a-Tube Platform.

Xiao N, Wang C, Yu C - Biosensors (Basel) (2013)

SERS spectra of silver nanoprobes with anti-E. coli antibodies interacted with E. coli and Listeria mixture sample solutions with different E. coli:Listeria ratio.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4263577&req=5

biosensors-03-00312-f007: SERS spectra of silver nanoprobes with anti-E. coli antibodies interacted with E. coli and Listeria mixture sample solutions with different E. coli:Listeria ratio.
Mentions: The specificity of the self-referencing dual-recognition scheme is determined by the specificity of the antibodies. As illustrated in Figure 7, when a sample with non-targets (L. monocytogenes, 103 CFU/mL) was integrated by the nanoprobes (specifically E. coli), no self-referencing signatures (735 cm–1, 825 cm–1 and 985 cm–1) were observed which resulted in a correct negative I.D. For a sample with a 10-fold higher non-targets (L. monocytogenes, 103 CFU/mL) concentration than target (E. coli, 102 CFU/mL), the specific E. coli peaks could still be identified, as shown in Figure 7. Relatively high level of interferences from other bacteria (L. monocytogenes) did not diminish the accuracy of the self-referencing dual-recognition scheme, indicating that this scheme would be extremely attractive to in-field pathogen detection applications, where interference from other co-existed microorganism species will be omnipresent.

Bottom Line: Anisotropic nanoparticles (i.e., silver nanocubes) were functionalized with target-specific antibodies and Raman active tags to serve as nanoprobes for the rapid detection of bacteria in a test-in-a-tube platform.The assessment through the dual signals (superimposed target and tag Raman signatures) supported a specific recognition of the targets in a single step with no washing/separation needed to a sensitivity of 102 CFU/mL, even in the presence of non-target bacteria at a 10 times higher concentration.The self-referencing protocol implemented with a portable Raman spectrometer potentially can become an easy-to-use, field-deployable spectroscopic sensor for onsite detection of pathogenic microorganisms.

View Article: PubMed Central - PubMed

Affiliation: Department of Agricultural and Biosystems Engineering, Iowa State University, Ames, IA 50011, USA. nxiao@iastate.edu.

ABSTRACT
Anisotropic nanoparticles (i.e., silver nanocubes) were functionalized with target-specific antibodies and Raman active tags to serve as nanoprobes for the rapid detection of bacteria in a test-in-a-tube platform. A self-referencing scheme was developed and implemented in which surface enhanced Raman spectroscopic (SERS) signatures of the targets were observed superimposed with the SERS signals of the Raman tags. The assessment through the dual signals (superimposed target and tag Raman signatures) supported a specific recognition of the targets in a single step with no washing/separation needed to a sensitivity of 102 CFU/mL, even in the presence of non-target bacteria at a 10 times higher concentration. The self-referencing protocol implemented with a portable Raman spectrometer potentially can become an easy-to-use, field-deployable spectroscopic sensor for onsite detection of pathogenic microorganisms.

No MeSH data available.


Related in: MedlinePlus