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Raman Spectroscopy Cell-based Biosensors

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ABSTRACT

One of the main challenges faced by biodetection systems is the ability to detect and identify a large range of toxins at low concentrations and in short times. Cell-based biosensors rely on detecting changes in cell behaviour, metabolism, or induction of cell death following exposure of live cells to toxic agents. Raman spectroscopy is a powerful technique for studying cellular biochemistry. Different toxic chemicals have different effects on living cells and induce different time-dependent biochemical changes related to cell death mechanisms. Cellular changes start with membrane receptor signalling leading to cytoplasmic shrinkage and nuclear fragmentation. The potential advantage of Raman spectroscopy cell-based systems is that they are not engineered to respond specifically to a single toxic agent but are free to react to many biologically active compounds. Raman spectroscopy biosensors can also provide additional information from the time-dependent changes of cellular biochemistry. Since no cell labelling or staining is required, the specific time dependent biochemical changes in the living cells can be used for the identification and quantification of the toxic agents. Thus, detection of biochemical changes of cells by Raman spectroscopy could overcome the limitations of other biosensor techniques, with respect to detection and discrimination of a large range of toxic agents. Further developments of this technique may also include integration of cellular microarrays for high throughput in vitro toxicological testing of pharmaceuticals and in situ monitoring of the growth of engineered tissues.

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Schematic representation of (A) Raman Stokes scattering of laser photons by vibrating molecules in the sample: energy is transferred by laser photons to the molecules as vibrational energy, the energy loss correspond to the vibrational energy levels of the molecules (E1, E2, …); and (B) experimental set-up for Raman spectroscopy measurements of cells.
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f1-sensors-07-01343: Schematic representation of (A) Raman Stokes scattering of laser photons by vibrating molecules in the sample: energy is transferred by laser photons to the molecules as vibrational energy, the energy loss correspond to the vibrational energy levels of the molecules (E1, E2, …); and (B) experimental set-up for Raman spectroscopy measurements of cells.

Mentions: When photons are incident on a sample, they can be scattered elastically (no change in energy) or inelastically (change in energy) by the sample. Raman spectroscopy is based on inelastic scattering of photons following their interaction with vibrating molecules of the sample. During this interaction, photons transfer (Stokes)/receive (Anti-Stokes) energy to/from molecules as vibrational energy. Thus, the energy change of the scattered photons corresponds to the vibrational energy levels of the sample molecules (Figure 1A). In Figure 1A, the energy levels E1, E2, E3 and E4 represent the fundamental vibrational levels (vibrational quantum number v=0) corresponding to normal vibrational modes of the molecule of frequencies ν1, ν2, ν3 and ν4. Since the vibrational energy spectrum depends on the chemical composition of the sample (type of atoms, bond strength, bond angles, symmetry, etc), a Raman spectrum has an unrivalled chemical specificity and represents a chemical fingerprint of the sample. For more detailed description of the physics of the Raman effect see references [28-30].


Raman Spectroscopy Cell-based Biosensors
Schematic representation of (A) Raman Stokes scattering of laser photons by vibrating molecules in the sample: energy is transferred by laser photons to the molecules as vibrational energy, the energy loss correspond to the vibrational energy levels of the molecules (E1, E2, …); and (B) experimental set-up for Raman spectroscopy measurements of cells.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3814856&req=5

f1-sensors-07-01343: Schematic representation of (A) Raman Stokes scattering of laser photons by vibrating molecules in the sample: energy is transferred by laser photons to the molecules as vibrational energy, the energy loss correspond to the vibrational energy levels of the molecules (E1, E2, …); and (B) experimental set-up for Raman spectroscopy measurements of cells.
Mentions: When photons are incident on a sample, they can be scattered elastically (no change in energy) or inelastically (change in energy) by the sample. Raman spectroscopy is based on inelastic scattering of photons following their interaction with vibrating molecules of the sample. During this interaction, photons transfer (Stokes)/receive (Anti-Stokes) energy to/from molecules as vibrational energy. Thus, the energy change of the scattered photons corresponds to the vibrational energy levels of the sample molecules (Figure 1A). In Figure 1A, the energy levels E1, E2, E3 and E4 represent the fundamental vibrational levels (vibrational quantum number v=0) corresponding to normal vibrational modes of the molecule of frequencies ν1, ν2, ν3 and ν4. Since the vibrational energy spectrum depends on the chemical composition of the sample (type of atoms, bond strength, bond angles, symmetry, etc), a Raman spectrum has an unrivalled chemical specificity and represents a chemical fingerprint of the sample. For more detailed description of the physics of the Raman effect see references [28-30].

View Article: PubMed Central

ABSTRACT

One of the main challenges faced by biodetection systems is the ability to detect and identify a large range of toxins at low concentrations and in short times. Cell-based biosensors rely on detecting changes in cell behaviour, metabolism, or induction of cell death following exposure of live cells to toxic agents. Raman spectroscopy is a powerful technique for studying cellular biochemistry. Different toxic chemicals have different effects on living cells and induce different time-dependent biochemical changes related to cell death mechanisms. Cellular changes start with membrane receptor signalling leading to cytoplasmic shrinkage and nuclear fragmentation. The potential advantage of Raman spectroscopy cell-based systems is that they are not engineered to respond specifically to a single toxic agent but are free to react to many biologically active compounds. Raman spectroscopy biosensors can also provide additional information from the time-dependent changes of cellular biochemistry. Since no cell labelling or staining is required, the specific time dependent biochemical changes in the living cells can be used for the identification and quantification of the toxic agents. Thus, detection of biochemical changes of cells by Raman spectroscopy could overcome the limitations of other biosensor techniques, with respect to detection and discrimination of a large range of toxic agents. Further developments of this technique may also include integration of cellular microarrays for high throughput in vitro toxicological testing of pharmaceuticals and in situ monitoring of the growth of engineered tissues.

No MeSH data available.


Related in: MedlinePlus