Limits...
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

Extinction spectra of of silver nanocube (PVP coated), 4-ATP-coated silver nanocube, and antibody-functionalized silver-nanocube probes.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4263577&req=5

biosensors-03-00312-f009: Extinction spectra of of silver nanocube (PVP coated), 4-ATP-coated silver nanocube, and antibody-functionalized silver-nanocube probes.

Mentions: Extinction spectra of silver nanocube (PVP coated, right after synthesis), 4-ATP-coated silver nanocube, and antibody-functionalized silver-nanocube probes are shown in Figure S2. After replacing the PVP coating with 4-ATP, the plasmonic peak blue-shifted, due to the change of refractive index (a reduction) and the thickness of the surface coating; the thinkness of the 4-ATP coating, which is a monolayer of small molecules, is much smaller than that of the PVP coating. After antibodies are conjugated to the 4-ATP linker, the plasmonic peak re-shifted slightly, due to the addition of the antibody molecules further increased the refractive index of the surface layer on the nanoparticles.


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)

Extinction spectra of of silver nanocube (PVP coated), 4-ATP-coated silver nanocube, and antibody-functionalized silver-nanocube probes.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

biosensors-03-00312-f009: Extinction spectra of of silver nanocube (PVP coated), 4-ATP-coated silver nanocube, and antibody-functionalized silver-nanocube probes.
Mentions: Extinction spectra of silver nanocube (PVP coated, right after synthesis), 4-ATP-coated silver nanocube, and antibody-functionalized silver-nanocube probes are shown in Figure S2. After replacing the PVP coating with 4-ATP, the plasmonic peak blue-shifted, due to the change of refractive index (a reduction) and the thickness of the surface coating; the thinkness of the 4-ATP coating, which is a monolayer of small molecules, is much smaller than that of the PVP coating. After antibodies are conjugated to the 4-ATP linker, the plasmonic peak re-shifted slightly, due to the addition of the antibody molecules further increased the refractive index of the surface layer on the nanoparticles.

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