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Modulated Raman Spectroscopy for Enhanced Cancer Diagnosis at the Cellular Level.

De Luca AC, Dholakia K, Mazilu M - Sensors (Basel) (2015)

Bottom Line: This innovative approach can be used to extract the Raman spectral component from the fluorescence background and improve the quality of the Raman signal.We describe the potential of modulated Raman spectroscopy as a rapid, inexpensive and accurate clinical tool to detect the presence of bladder cancer cells.Finally, in a broader context, we show how this approach can greatly enhance the sensitivity of integrated Raman spectroscopy and microfluidic systems, opening new prospects for portable higher throughput Raman cell sorting.

View Article: PubMed Central - PubMed

Affiliation: Institute of Protein Biochemistry, National Research Council, Via P. Castellino, 111, 80131 Naples, Italy. a.deluca@ibp.cnr.it.

ABSTRACT
Raman spectroscopy is emerging as a promising and novel biophotonics tool for non-invasive, real-time diagnosis of tissue and cell abnormalities. However, the presence of a strong fluorescence background is a key issue that can detract from the use of Raman spectroscopy in routine clinical care. The review summarizes the state-of-the-art methods to remove the fluorescence background and explores recent achievements to address this issue obtained with modulated Raman spectroscopy. This innovative approach can be used to extract the Raman spectral component from the fluorescence background and improve the quality of the Raman signal. We describe the potential of modulated Raman spectroscopy as a rapid, inexpensive and accurate clinical tool to detect the presence of bladder cancer cells. Finally, in a broader context, we show how this approach can greatly enhance the sensitivity of integrated Raman spectroscopy and microfluidic systems, opening new prospects for portable higher throughput Raman cell sorting.

No MeSH data available.


Related in: MedlinePlus

(a) Comparison of standard and modulated Raman spectra of a 400 mM urea concentration acquired in the wave guide-confined Raman spectroscopy configuration; (b) urea concentration vs. SNR for standard Raman (cyan) and modulated Raman (green) spectra; (c) variation of SNR in relation to the acquisition time for the Raman peak of urea at a 300 mM concentration in modulated Raman spectra [68]. The modulated Raman spectra of the 300 mM urea concentration acquired at different integration times are additionally shown.
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f11-sensors-15-13680: (a) Comparison of standard and modulated Raman spectra of a 400 mM urea concentration acquired in the wave guide-confined Raman spectroscopy configuration; (b) urea concentration vs. SNR for standard Raman (cyan) and modulated Raman (green) spectra; (c) variation of SNR in relation to the acquisition time for the Raman peak of urea at a 300 mM concentration in modulated Raman spectra [68]. The modulated Raman spectra of the 300 mM urea concentration acquired at different integration times are additionally shown.

Mentions: In Figure 11b, it can be seen that the detection limit is only slightly smaller for modulated Raman spectroscopy, while the sensitivity of the device (slope of the curves in Figure 11b), which strongly depends on the spectra SNR influenced by background fluorescence, is seven-times increased for modulated Raman compared to that of the standard Raman spectra. This means that the resolution and robustness of WCRS for concentration prediction has significantly been enhanced with the implementation of the fluorescent suppression technique. Additionally, directly comparing the standard Raman spectrum obtained with an integration time of 100 s and the modulated Raman spectrum obtained with an integration time of only 20 s, we can clearly assess that the SNR values are comparable (see Figure 11c). This result demonstrates that the modulated Raman spectroscopy not only allows us to remove the fluorescence background, but also clearly improves the SNR, reducing the required acquisition time. Therefore, there is a great potential for WCRS to be used for developing alignment-free sensing optofluidic devices that can detect bioanalytes with minimal sample preparation.


Modulated Raman Spectroscopy for Enhanced Cancer Diagnosis at the Cellular Level.

De Luca AC, Dholakia K, Mazilu M - Sensors (Basel) (2015)

(a) Comparison of standard and modulated Raman spectra of a 400 mM urea concentration acquired in the wave guide-confined Raman spectroscopy configuration; (b) urea concentration vs. SNR for standard Raman (cyan) and modulated Raman (green) spectra; (c) variation of SNR in relation to the acquisition time for the Raman peak of urea at a 300 mM concentration in modulated Raman spectra [68]. The modulated Raman spectra of the 300 mM urea concentration acquired at different integration times are additionally shown.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4507596&req=5

f11-sensors-15-13680: (a) Comparison of standard and modulated Raman spectra of a 400 mM urea concentration acquired in the wave guide-confined Raman spectroscopy configuration; (b) urea concentration vs. SNR for standard Raman (cyan) and modulated Raman (green) spectra; (c) variation of SNR in relation to the acquisition time for the Raman peak of urea at a 300 mM concentration in modulated Raman spectra [68]. The modulated Raman spectra of the 300 mM urea concentration acquired at different integration times are additionally shown.
Mentions: In Figure 11b, it can be seen that the detection limit is only slightly smaller for modulated Raman spectroscopy, while the sensitivity of the device (slope of the curves in Figure 11b), which strongly depends on the spectra SNR influenced by background fluorescence, is seven-times increased for modulated Raman compared to that of the standard Raman spectra. This means that the resolution and robustness of WCRS for concentration prediction has significantly been enhanced with the implementation of the fluorescent suppression technique. Additionally, directly comparing the standard Raman spectrum obtained with an integration time of 100 s and the modulated Raman spectrum obtained with an integration time of only 20 s, we can clearly assess that the SNR values are comparable (see Figure 11c). This result demonstrates that the modulated Raman spectroscopy not only allows us to remove the fluorescence background, but also clearly improves the SNR, reducing the required acquisition time. Therefore, there is a great potential for WCRS to be used for developing alignment-free sensing optofluidic devices that can detect bioanalytes with minimal sample preparation.

Bottom Line: This innovative approach can be used to extract the Raman spectral component from the fluorescence background and improve the quality of the Raman signal.We describe the potential of modulated Raman spectroscopy as a rapid, inexpensive and accurate clinical tool to detect the presence of bladder cancer cells.Finally, in a broader context, we show how this approach can greatly enhance the sensitivity of integrated Raman spectroscopy and microfluidic systems, opening new prospects for portable higher throughput Raman cell sorting.

View Article: PubMed Central - PubMed

Affiliation: Institute of Protein Biochemistry, National Research Council, Via P. Castellino, 111, 80131 Naples, Italy. a.deluca@ibp.cnr.it.

ABSTRACT
Raman spectroscopy is emerging as a promising and novel biophotonics tool for non-invasive, real-time diagnosis of tissue and cell abnormalities. However, the presence of a strong fluorescence background is a key issue that can detract from the use of Raman spectroscopy in routine clinical care. The review summarizes the state-of-the-art methods to remove the fluorescence background and explores recent achievements to address this issue obtained with modulated Raman spectroscopy. This innovative approach can be used to extract the Raman spectral component from the fluorescence background and improve the quality of the Raman signal. We describe the potential of modulated Raman spectroscopy as a rapid, inexpensive and accurate clinical tool to detect the presence of bladder cancer cells. Finally, in a broader context, we show how this approach can greatly enhance the sensitivity of integrated Raman spectroscopy and microfluidic systems, opening new prospects for portable higher throughput Raman cell sorting.

No MeSH data available.


Related in: MedlinePlus