The CARS images of Thy/GO recorded at several wavenumbers are shown in Figure 9. The
bands at 1,365 and 1,670 cm-1 and at 2,930, 3,065, and 3,300 cm-1 are used to obtain the images of two different fragments of the sample. Scans at 2,930, 3,065, and 3,300 cm-1 were done in 50 × 50-μm area and show the typical fragment entirely. All images have a very high contrast with respect to the image at 3,300 cm-1, where the background at non-resonance wavenumber is shown. It should be mentioned on the basis of comparison (Figure 9a,c) that the intensity of the CARS band at 2,930 cm-1 of Thy/GO is higher than that at 1,365 cm-1 (one of the most intensive bands). This fact supports
our assumption regarding VX-680 the interaction between Thy and GO modes. Figure 9 CARS (a,b,c,d,e) images of the Thy/GO complex. So, from the CARS images, it is seen that the Thy/GO complex Flavopiridol chemical structure adsorbed on the glass surface is not as a solid film but rather as flat flakes with lateral size from 1 to 15 μm. It is important to note that the most intensive CARS bands of GNPs and Thy/GO are, respectively, at 2,960 and at 2,930 cm-1. So, it could be supposed that the enhancement of the CARS bands of the Thy/GO complex in the 2,930- to 3,100 cm-1-range is LXH254 mouse connected with the chemical interaction between Thy and GO. The Raman spectra of Thy and oxyclozanide the Thy/GO complex are shown in Figure 10. In the spectra of Thy/GO, the characteristic bands of GO (D-, G-, and 2D-modes) are clearly seen. Also, in the 2,750- to 3,200-cm-1 range, the enhancement and widening of the characteristic
bands of Thy are observed. Importantly, these bands are the features of the CARS spectra as well (Figure 8). Figure 10 Raman spectra of Thy (1) and Thy/GO (2) at λ ex = 785 nm. (a) In 1,200 to 1,700 cm -1 range. (b) In 2,400 to 3,200 cm-1 range. The modes of GO are labeled by asterisks (*). The assignment of Raman and CARS spectral bands for Thy and Thy/GO complex is presented in Table 3. As a whole, the position of the bands in the Raman and CARS spectra is often close. In the CARS spectrum of the Thy/GO complex, there are NH and CH stretching modes in the 3,000- to 3,300-cm-1 range, and the C6H stretching modes of medium intensity are at 3,065 cm-1. It is interesting that in the CARS spectra of the Thy/GO complex (Table 4), there is only one band at 1,670 cm-1, whereas in the corresponding spectra of Thy, there are two bands at 1,655 and 1,660 cm-1, attributed to C4O and C2O stretching modes, respectively. A similar effect was observed in the case of SERS of Thy on gold in comparison with RS of those ; however, its nature could have another origin.