Biofunctionalization of multi-walled carbon nanotubes with L-Alanine

Abstract

In the present investigation, L-Alanine (Ala) amino acid functionalized Multi-walled carbon nanotubes (MWCNTs) were synthesized and its physico-chemical properties were studied. The observed shift in the XRD peak value indicates the attachment of the Ala on the MWCNTs. The obtained new characteristic peak in the UV–vis spectrum of Ala functionalized MWCNTs confirms the biofunctionalization of Ala. SEM micrographs reveal that the nanotubular structure of the MWCNTs, which were not affected during the biofunctionalization process. EDAX analysis confirms the percentage of various elements in the biofunctionalized MWCNTs. Significantly, the presence of nitrogen element in the EDAX analysis reveals the successful biofunctionalization of MWCNTs. TEM studies show the clear morphological changes between the oxidized and biofunctionalized MWCNTs. Raman spectral analysis of Ala functionalized MWCNTs shows an increase in the intensity ratio when compared to that of the oxidized MWCNTs, which confirms the higher degree of biofunctionalization. FT-IR studies verify the presence of new functional group, which is the evident for the biofunctionalization of Ala onto the surface of the MWCNTs. Thus, the present innvestigation results in the stable dispersion in organic solvents. Biofunctionalization leads to the production of less toxic, biocompatible, eco friendly MWCNTs. This process removes the metallic impurities. The Ala attachment on the MWCNTs will improve the interaction between biofunctionalized MWCNTs and various polymers and monomers. The terminal carboxylic acid present on the Ala are hydrophilic and can be useful for further chemistry and covalent binding with other biomolecules. The amino acid based biodegradable polymers are highly useful in tissue engineering. Thus, Ala functionalized MWCNTs will act as a initial step for the attachment of biodegradable polymers to the MWCNTs, which will enhance the biomedical applications in the field of tissue engineering.