An amino acid, L-Glutamic acid-based metal-organic frameworks and their antibacterial, blood compatibility, biocompatibility, and sensor properties

Abstract

In this study, metal-organic frameworks (MOFs) based on L-Glutamic acid (L-Glu), a natural amino acid as organic linker and Co (II), Ni (II), and Cu (II) metal ions were used in construction with 37.1 ± 5.3%, 41.4 ± 6.1%, 49.2 ± 4.9% yields, respectively in ethanol under reflux. The prepared L-Glu-M (M: Co(II), Ni(II), and Cu(II)) MOFs were characterized in terms of their porosity, optical, thermal, electrical, and structural properties. Correspondingly, 102.1 m2/g, 83.7 m2/g, and 71.0 m2/g specific surface areas and 2.72 cm3/g, 0.46 cm3/g, and 0.07 cm3/g pore volumes were measured for L-Glu-based Co, Ni, and Cu MOFs. Moreover, the antimicrobial studies of L-Glu-M MOFs on Escherichia coli ATCC 8739, as gram-negative, and Staphylococcus aureus ATCC 6538 as gram-positive bacteria revealed that the highest inhibition zones with 42 ± 2 mm and 44 ± 1 mm were observed for L-Glu-Co MOFs. The hemolysis induction of L-Glu-M MOFs was evaluated, except L-Glu-Cu that induced 8.3 ± 0.4% hemolysis, and the hemolytic characters of other MOF preparations were found to reside in safety margins possessing ≤4% hemolysis ratios. The blood clotting index of L-Glu-M MOFs were measured as 87.4 ± 6.3% (Co(II)), 91.8 ± 10.1% (Ni(II)), and 95.7 ± 4.8% (Cu(II)) with neglectable interference to clotting mechanisms. Cytocompatibility of L-Glu-based MOFs were demonstrated that all MOF preparations with 25 μg/mL concentrations maintained approximately 90% cell viabilities. Furthermore, Glu-based MOFs were demonstrated to possess sensory properties for NH3 vapor and could be employed in at least five cycles of repeated use. Therefore, L-Glu-M based MOFs can provide useful avenues in material science for a variety of biomedical and industrial applications.