A Nitroreductase-MOF Biocatalyst for the Degradation of Nitroaromatic Contaminants and Fluorescent Labelling of Biomolecules.

NfsB (nitroreductase from Escherichia coli) can catalyze nitroaromatic compounds to aromatic amines under mild conditions. Compared with the purified enzyme NfsB, we found that the crude enzyme demonstrated better thermal stability and tolerance against a wide pH range, rendering it convenient to use and cost-effective as it did not require any downstream processing. In addition, we introduced metal-organic frameworks (MOFs) to immobilize the crude-NfsB. The resulting composite, crude-NfsB@ZIF-90, showed excellent catalytic performance and reusability, and it also demonstrated good catalytic activity in organic solvents, rendering it more efficient for the removal of nitroaromatic contaminants in complex environments. The nitroreductase-ZIF-90 biocatalyst can be used for fluorescent labeling of carbohydrates, which is favorable for the study of the function of carbohydrates.