(101h) Amino Acid-Based Metal Organic Frameworks: Synthesis, Characterization, and Potential Biomedical Applications

A coordination complex consists of a central atom or ion that is usually a metal and called as the coordination center, and around this center there are arrangements of bound molecules or ions, that are called as ligands or linkers. In the recent years, metal organic frameworks (MOFs) have attracted great attention due to their intriguing properties and promising potential in diverse applications including sensor, catalysis, storage, adsorption and separation of gas mixtures e.g., H₂, N₂, CO₂, NH₃, H₂S, and CH₄ etc. In the last decade, MOFs with different porosity and characteristic were prepared with designed properties by controlling various parameters such as the starting material sizes and the functionality of the linkers and as well as their tendency to interact with some different side functional groups that can also be post modifiable. Recently, linkers from natural source offered promising avenues to organic toxic compounds as benign and non-toxic alternatives. An amino acid, L-Glutamic acid with one amine and two carboxylic acid groups was reported for metal binding capability. Each of these functional groups is capable of binding to metal centers and glutamate has a variety of coordination modes making it a potential natural organic linker for the construction of MOF materials [1].

In this study, amino acid based MOFs were constructed employing L-Glutamic acid (L-Glu) as organic linker and acetate salts of Co(II), Ni(II), Cu(II), and Zn(II) and etc under ethanol reflux using a condenser. The prepared L-Glu-M (M:Co, Ni, Cu, and Zn etc) MOFs were characterized in terms of their porosity, optical, thermal, electrical and structural properties by using Brunauer–Emmett–Teller (BET) measurements, UV-Vis and Fluorescence spectroscopy, Optic and Scanning Electron Microscopy (SEM), Fourier Transform infrared (FT-IR) spectroscopy, Thermogravimetric Analysis (TGA), and X-ray diffraction (XRD) analysis and so on. Moreover, the bio-compatibility, blood-compatibility, and antimicrobial properties of these prepared L-Glu-M MOFs were investigated and compared with each other. Additionally, the potential use of the prepared L-Glu-M MOFs as sensor against HCl and NH₃ vapors were tested by means of the change in the electrical conductivity of these MOFs before and after exposure to the corresponding vapors.

[1] P. Long, Q. Zhao, J. Dong, J. Li, J. Coor. Chem., 62 (2009), 1959-1963.