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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

Raman spectra of Ag nanocube with antibodies conjugated to them.
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biosensors-03-00312-f010: Raman spectra of Ag nanocube with antibodies conjugated to them.

Mentions: Figure S3 shows the Raman spectra of PVP-coated silver nanocube, 4-ATP-coated silver nanocube and anti-E. coli antibody-conjugated silver nanocube. A layer of 4-ATP molecules were anchored on the surface of the silver nanotubes after incubation with the Ag-cube solution due to Ag–S bonding. As shown in Figure S2, band at 1,090 cm−1 is the stretching vibration of C–S bond and band at 1,590 cm−1 is the C–C stretching vibration of benzene ring in 4-ATP [29,30,31,32,33]. The appearance of these bands, replacing the original PVP bands, indicated the successful replacement of PVP with 4-ATP on the Ag-cube surface. Another notable difference between the spectra of pure 4-ATP and that of 4-ATP labeled Ag-cube is the intensity of 4-ATP characteristic peak at 1,590 cm−1. The apparent enhancement of the mode at 1,590 cm−1 can be ascribed to a charge transfer between the metal and the 4-ATP molecules [9], further confirms the binding of 4-ATP to the Ag-cube surfaces.


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)

Raman spectra of Ag nanocube with antibodies conjugated to them.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

biosensors-03-00312-f010: Raman spectra of Ag nanocube with antibodies conjugated to them.
Mentions: Figure S3 shows the Raman spectra of PVP-coated silver nanocube, 4-ATP-coated silver nanocube and anti-E. coli antibody-conjugated silver nanocube. A layer of 4-ATP molecules were anchored on the surface of the silver nanotubes after incubation with the Ag-cube solution due to Ag–S bonding. As shown in Figure S2, band at 1,090 cm−1 is the stretching vibration of C–S bond and band at 1,590 cm−1 is the C–C stretching vibration of benzene ring in 4-ATP [29,30,31,32,33]. The appearance of these bands, replacing the original PVP bands, indicated the successful replacement of PVP with 4-ATP on the Ag-cube surface. Another notable difference between the spectra of pure 4-ATP and that of 4-ATP labeled Ag-cube is the intensity of 4-ATP characteristic peak at 1,590 cm−1. The apparent enhancement of the mode at 1,590 cm−1 can be ascribed to a charge transfer between the metal and the 4-ATP molecules [9], further confirms the binding of 4-ATP to the Ag-cube surfaces.

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