Enhancing the Raman Scattering for Diagnosis and Treatment of Human Cancer Cells , Tissues and Tumors Using Cadmium Oxide ( CdO ) Nanoparticles

In the current paper, the Localized Surface Plasmon Resonance (LSPR) effect induced by Cadmium Oxide (CdO) nanoparticles is used to observe Raman spectrum of human cancer cells, tissues and tumors. The diagnosis and treatment of human cancer cells, tissues and tumors in sample is investigated through Nanomaterial Surface Energy Transfer (NSET) process from human cancer cells, tissues and tumors to the surface of nanoparticles, and Surface Enhanced Raman Scattering (SERS) process, as effective factors for Raman spectrum detection. For interaction of human cancer cells, tissues and tumors with Cadmium Oxide (CdO) nanoparticles, colloidal state and Self-Assembled Monolayer (SAM) methods were used. Both methods have shown good agreement with each other in detecting the Raman spectrum. It should be noted that these methods and techniques can be applied on different types of human’s cancer cells, tissues and tumors, respectively.

In addition, utilizing Plasmon structures leads to increase the maximum effective distance of Forster (fluorescence) Resonance Energy Transfer (FRET) from 10 (A°) to 220 (A°).This process of energy transfer between fluorophore and surface of nanoparticle named as Nanomaterial Surface Energy Transfer (NSET).In this condition, the quantum gain of energy transfer is defined as:

Introduction
Since the discovering time of Raman scattering, a great effort has been begin to enhance Raman signal for increasing the detection limit and sensitivity of this method due to inherent low scattering cross section of Raman.Today, Plasmon structures are widely used to enhance Raman signal.This method is known as Surface Enhanced Raman Scattering (SERS) .The En-• Page 2 of 14 • As Plasmon modes are mainly damped in non-radiant form, this process can be led to considerable reduction of fluorescence in the sample.Domination of each of these two processes and its intensity are depend on factors such as overlapping of nanoparticle absorption spectrum with fluorescence spectrum of sample, distance and relative direction between them, size and form of nanoparticles and etc. [107 -161].
In the current paper, SERS spectrum of a very light emissive sample of human cancer cells, tissues and tumors is obtained at colloidal condition and over the substrate monolayer produced using Self-Assembled Monolayer (SAM) method and the effects of enhanced Raman scattering and NSET are studied for observing the spectrum of these human cancer cells, tissues and tumors.It should be noted that these methods and techniques can be applied on different types of human's cancer cells, tissues and tumors, respectively .
SERS spectra for samples were obtained using the designed arrangement for Raman spectroscopy.A schematic view of this arrangement is shown in (Figure 1).A laser with 532 (nm) wavelength was used as excitation source.Laser light was focused on the sample by a 4X thing and the scattered Raman signal was collected by that thing and was sent to spectrometer for analysis.

Sample preparation method
Nanoparticles were synthesized based on Alireza Heidari and Christopher Brown method [1].Briefly, 18 (mg) Cadmium Oxide (CdO) nanoparticles solution was heated up to boiling point at 90 (ml) water.Then, 2 (ml) of 1% citrate solution was added to it and was maintained at boiling point for 90 minutes [1].
The glassy substrates activated with hydroxyl group were placed in 1% solution of APTES for 4 hours.After washing with toluene, substrates were submerged into colloidal Cadmium Oxide (CdO) nanoparticles solution for 24 hours and then, were maintained into the water up to the time for using.To measure the Raman spectrum of human cancer cells, tissues and tumors, substrates were placed in 1 (μM) solution of sample and then, Raman spectrum was measured.
To observe SERS signal at colloidal state, at least 3 hours before the test, 0.01 (M) solution of NaCl and 1 (μM) solution of human cancer cells, tissues and tumors were added to Cadmium Oxide (CdO) nanoparticles.

Results and Discussion
The general scheme of formation mechanism of substrate is shown in (Figure 2).states over a glassy medium.Maximum Plasmon resonance at colloidal state is about 453 (nm).However, this maximum for the substrates produced using self-assembled method shows a shift towards shorter wavelengths (418 nm).This shift can be attributed to dipole-dipole interaction between arrayed nanoparticles in a two-dimensional structure.Further, a new peak is emerged around 710 (nm) due to pairing of nanoparticles.placed as two-dimensional arrays over glassy medium.This overlapping is necessary for energy transferring.
As the synthesized nanoparticles are mainly spherical, energy transferring process is independent of emission direction of incident light.Spectroscopy was performed during 5 seconds for all samples.In this comparison, fluorescence human cancer cells, tissues and tumors spectrum is attenuated up to 25 times due to high concentration of fluorescence in 1 (μM) solution of human cancer cells, tissues and tumors molecules and saturation of spectrometer (Figure 4c).
Table 1 shows vibration modes related to human cancer cells, tissues and tumors molecules.Frequency shift of this test is compared with a reference which its results show good agreement with reference results [1].

Conclusions, Perspectives, Useful Suggestions and Future Studies
The results obtained in the current study show the effect of Cadmium Oxide (CdO) nanoparticles on Raman spectrum detection through two mechanisms of SERS and NSET.In order to confirm the effect of nanoparticles on various conditions, colloidal and self-assembled monolayer mediums were used.The results obtained from both states are in good agreement with each other.147.Alireza Heidari (2018) Small-angle X-ray scattering (SAXS), ultra-small angle X-ray scattering (USAXS), fluctuation X-ray scattering (FXS), wide-angle X-ray scattering (WAXS), grazing-incidence small-angle X-Ray scattering (GISAXS), grazing-incidence wide-angle X-ray scattering (GIWAXS), small-angle neutron scattering (SANS), grazing-incidence small-angle neutron scattering (GISANS), X-ray diffraction (XRD), powder X-ray diffraction (PXRD), wide-angle X-ray diffraction (WAXD), grazing-incidence X-ray diffraction (GIXD) and energy-dispersive X-ray diffraction (EDXRD) comparative study on malignant and benign human cancer cells and tissues under synchrotron radiation.Oncol Res Rev 1: 1-10.
148.Alireza Heidari (2018) Pump-probe spectroscopy and transient grating spectroscopy comparative study on malignant and benign human cancer cells and tissues with the passage of time under synchrotron radiation.Adv Material Sci Engg 2: 1-7.
where d 0 is the distance in which fluorophore has a same probability for emission and energy transfer to nanoparticle [76-106].The emitted fluorescence signal by molecule can be enhance by Plasmon field at the vicinity of nanoparticle either at emissive wavelength or at excitation wavelength.At the other hand, fluorescence signal of molecule can be transferred to the neighboring nanoparticle through non-radiant process of NSET.

Figure 3 Figure 1 :
Figure3shows absorption spectrum of Cadmium Oxide (CdO) nanoparticles at colloidal and self-assembled

Figure 2 :
Figure 2: Various stages of formation of substrate; a) Cleaning and activating the glassy medium; b) Surface functionalizing using silane group and; c) Connection of nanoparticles to the surface using silane group.

Figure 4a andFigure 3 :Figure 4 :
Figure 4a and Figure 4b show the enhanced Raman spectrum of human cancer cells, tissues and tumors 150.Alireza Heidari (2018) Acoustic spectroscopy, acoustic resonance spectroscopy and auger spectroscopy comparative study on anti-cancer nano drugs delivery in malignant and benign human cancer cells and tissues with the passage of time under synchrotron radiation.Nanosci Technol 5: 1-9.151.Alireza Heidari (2018) Niobium, technetium, ruthenium, rhodium, hafnium, rhenium, osmium and iridium ions incorporation into the nano polymeric matrix (NPM) by immersion of the nano polymeric modified electrode (NPME) as molecular enzymes and drug targets for human cancer cells, tissues and tumors treatment under synchrotron and synchrocyclotron radiations.Nanomed Nanotechnol.152.Alireza Heidari (2018) Homonuclear correlation experiments such as homonuclear single-quantum correlation

Table 1 :
Raman vibrational modes of human cancer cells, tissues and tumors molecules.