Oxidized multiwalled carbon nanotubes were functionalized with proline using a simple ultrasonic blending process. This work is a preliminary studies of analyzing the functionalization of L-Proline (L-Pro) with MWCNTs . The chemical attachment of L-Pro on CNTs is of significant interest, since it not only improve the nanotube solubility but also opens a broad prospect for their biomedical applications. The interaction between the CNTs and amino acid is very important for understanding the interaction mechanism between CNTs and biomolecules. The various properties of the functionalized samples were evaluated by the spectroscopic characterization techniques like X-ray diffraction, UV–Vis, Scanning electron microscopy, Transmission electron microscope, Fourier transform infrared and Raman analysis. The observed sharp peaks attributes to the higher degree of crystalline nature. The shift in the XRD pattern indicates that the attachment of L-Pro on the surface of oxidized MWCNTs. The appearance of new peaks are due to the presence of the L-Pro on the MWCNTs, which confirms the attachment of the Pro on the surface of the MWCNTs. The UV–Vis spectra shows the shift in the lower cut off wavelength of the L-Pro functionalized MWCNTs, which confirms the successful attachment of the L-Pro on the surface of the MWCNTs. From the UV analysis, the new broad characteristic peaks appeared at 381 nm, 387 nm, 388 nm of L-Pro functionalized MWCNTs can be attributed to the charge transfer complex available on the MWCNTs. The L-Proline functionalized MWCNTs shows a high surface roughness, which is due to the partial damage of the graphitic carbon during functionalization. The presence of C–N stretching vibrations confirm the successful functionalization. The higher intensity ratio reveals that the greater extent of C=C rupture, which indicates the higher covalent functionalization on the surfaces of the MWCNTs. The enhancement of the I_D/I_G ratio of L-Pro functionalized MWCNTs are due to the amidation, which is the carboxylic acid group of oxidized MWCNTs reacts with the amino groups of Proline and due to the results of the radical reaction with MWCNTs. The g-values from EPR analysis confirms that the system remains isotropic which is due to the finite unpaired electron density. Hence, the successful functionalization of MWCNTs with L-Proline is confirmed, which is highly useful for further chemistry with other biomolecules like peptides, proteins and also leads to the research for the treatment of neuro degenerative diseases.

使用简单的超声混合工艺，用脯氨酸将氧化的多壁碳纳米管功能化。这项工作是分析MWCNTs对L-脯氨酸（L-Pro）的功能化的初步研究。L-Pro在CNT上的化学连接引起人们极大的兴趣，因为它不仅提高了纳米管的溶解度，而且为其生物医学应用打开了广阔的前景。碳纳米管与氨基酸之间的相互作用对于理解碳纳米管与生物分子之间的相互作用机制非常重要。通过光谱表征技术，如X射线衍射，UV-Vis，扫描电子显微镜，透射电子显微镜，傅立叶变换红外光谱和拉曼分析，对功能化样品的各种性能进行了评估。观察到的尖峰归因于较高程度的结晶性质。XRD图谱的移动表明L-Pro在氧化的MWCNT表面上的附着。新峰的出现归因于MWCNT上L-Pro的存在，这证实了Pro在MWCNTs表面上的附着。UV-Vis光谱显示了L-Pro功能化的MWCNT的较低截止波长的偏移，这证实了L-Pro成功地附着在MWCNTs的表面上。从UV分析中，L-Pro功能化的MWCNT出现在381 nm，387 nm，388 nm处的新的宽特征峰可归因于MWCNT上可用的电荷转移复合物。L-脯氨酸官能化的MWCNT具有很高的表面粗糙度，这是由于功能化过程中石墨碳的部分损坏。C–N拉伸振动的存在证实了功能化的成功。强度比越高，表明C = C断裂的程度越大，这表明MWCNTs表面上的共价官能化程度越高。的增强L-Pro功能化的MWCNT的I _D / I _G比归因于酰胺化，这是氧化的MWCNT的羧酸基与脯氨酸的氨基反应，以及与MWCNT发生自由基反应的结果。EPR分析的g值证实系统是各向同性的，这是由于有限的不成对电子密度所致。因此，证实了用L-脯氨酸成功地将MWCNT官能化，这对于与其他生物分子如肽，蛋白质的进一步化学非常有用，并且还导致了对神经退行性疾病的治疗的研究。