Hydrogel–Metal–Organic-Framework Nanoparticle Composites for Immobilization of Active Biomacromolecules

Immobilization of biomacromolecules offers a favorable protocol for promoting their practical application in biocatalysis, biosensing, and biopharmaceuticals. However, many biomacromolecules are susceptible to deactivation due to the harsh synthetic environment. Here, a simple, scalable, and easily manageable strategy was reported to immobilize several enzymes on the hydrogel–metal–organic-framework nanoparticle composites (HMOFNCs) prepared by simple mixing. That is to say, HMOFNCs are prepared by adding ligands to a metal nitrate mixing solution containing melamine and salicylic acid. Both proteins and DNAs could be immobilized on the surface of HMOFNCs, and their active conformation can be maintained by protecting the biomacromolecules. Moreover, the performance of the biomacromolecules-on HMOFNCs could be fine-tuned by controlling the size of HMOFNCs via the introduction of different amounts of hydrogels. Besides, TPL-on-HMOFNCs also displayed much higher operational stability with a lower loss of conversion rates before six repeated cycles. It is demonstrated that HMOFNCs with the immobilization of active biomacromolecules via simple mixing have great prospects in some significant fields, such as sensing, catalysis, and biomedicine.