Biomimetic Mineralization of Metal Ion‐Doped Lipase into ZIF‐8 Framework for Enhanced Hydrolytic Activity in Biphasic System.

Present work encapsulated metal ion dopped‐Candida rugosa lipase (CRL) into ZIF structure through biomimetic mineralization and evaluated hydrolytic activity of the immobilized lipase using a biphasic system. Magnesium ion (Mg2+) doped‐CRL with high hydrolytic activity (237 % of free CRL) was successfully synthesized. Circular dichroism and fluorescence spectroscopy analysis revealed Mg2+ doping has changed the conformation of CRL resulted in enhanced structural stability of CRL. The synthesized CRL/Mg2+@ZIF‐8 had a mesoporous (3.88 nm) structure with good crystallinity. Mg2+ doping increased the catalytic activity, substrates affinity (lower Km of 0.4102 mM) and catalytic stability of immobilized CRL. Catalytic activity of CRL/Mg2+@ZIF‐8 (0.25±0.012 U) was two‐fold higher than that of CRL@ZIF‐8 (0.10±0.008 U). The synthesized CRL/Mg2+@ZIF‐8 was used in biosensing of a protox‐inhibiting herbicides (nitrofen) in fruit samples. CRL/Mg2+@ZIF‐8 can be used for biosensing of nitrofen with wide detection range (0‐50 μM), low detection limit (0.47 μM) and good recovery rate. [ABSTRACT FROM AUTHOR]