Co-immobilization of multiple enzymes by metal coordinated nucleotide hydrogel nanofibers: improved stability and an enzyme cascade for glucose detection

Abstract

Preserving enzyme activity and promoting synergistic activity via co-localization of multiple enzymes are key topics in bionanotechnology, materials science, and analytical chemistry.This study reports a facile method for co-immobilizing multiple enzymes in metal coordinated hydrogel nanofibers. Specifically, four types of protein enzymes, including glucose oxidase, Candida rugosa lipase, α-amylase, and horseradish peroxidase were respectively encapsulated in a gel nanofiber made of Zn 2+ and adenosine monophosphate (AMP) with a simple mixing step. Most enzymes achieved quantitatively loading and retained full activity. At the same time, the entrapped enzymes were more stable against temperature variation (by 7.5 C), protease attack, extreme pH (by 2-fold), and organic solvents. After storage for 15 days, the entrapped enzyme still retained 70% activity while the free enzyme nearly completely lost activity. Compared to nanoparticles formed with AMP and lanthanide ions, the nanofiber gels allowed much higher enzyme activity. Finally, a highly sensitive and selective biosensor for glucose was prepared using the gel nanofiber to co-immobilize glucose oxidase and horseradish peroxidase for an enzyme cascade system. A detection limit of 0.3 µM glucose with excellent selectivity was achieved. This work indicates that metal coordinated materials using nucleotides are highly useful for interfacing with biomolecules.3

Magnetic Iron Oxide Nanoparticle Seeded Growth of Nucleotide Coordinated Polymers

“…The CP shell material alone should be able to encapsulate BSA, and we previously demonstrated protein encapsulation using Zn 2+ /AMP. 43 It is likely that the CP grows around each protein to achieve encapsulation. 14 The encapsulation of DNA was next tested.…”

“…Therefore, encapsulating GOx into the CP layer may establish an enzyme cascade system such that the in-situ generated H2O2 can be efficiently used by the surrounding nanozyme ( Figure 5A). 43,[51][52][53][54][55] At the same time, the CP shell may also protect GOx. To test this, we first evaluated the encapsulation efficiency of…”

Carbon nanofiber modified with osmium based redox polymer for glucose sensing

“…Enzyme immobilization techniques are the key in improving its performance. Recently, nanofibers have shown to be ideal in immobilization of enzymes [13,14]. Carbon nanofibers made from nylon have been used for biosensing applications due to their excellent stability and biocompatibility [15,16].…”

In-Situ Self-Assembly of Zinc/Adenine Hybrid Nanomaterials for Enzyme Immobilization

“…To solve these issues, immobilization techniques are considered, because binding of free enzymes to supports limits their mobility [8]. What is more, some immobilized enzymes could show more robust activity than free enzymes [9][10][11][12].…”