title: 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 quantitative 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 storing for 15 days, the entrapped enzyme still retained 70% activity while the free enzyme nearly completely lost its 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.
authors.affiliation: State key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing, P.R. China. lianghao@mail.buct.edu.cn.
authors.forename: Hao
authors.initials: H
authors.lastname: Liang
authors.forename: Shuhui
authors.initials: S
authors.lastname: Jiang
authors.forename: Qipeng
authors.initials: Q
authors.lastname: Yuan
authors.forename: Guofeng
authors.initials: G
authors.lastname: Li
authors.forename: Feng
authors.initials: F
authors.lastname: Wang
authors.forename: Zijie
authors.initials: Z
authors.lastname: Zhang
authors.forename: Juewen
authors.initials: J
authors.lastname: Liu
mesh_terms: D015374:Biosensing Techniques; D002175:Candida / Q000201:enzymology; D002384:Catalysis; D004800:Enzymes, Immobilized / Q000737:chemistry*; D005782:Gels / Q000737:chemistry; D005947:Glucose / Q000737:chemistry*; D005949:Glucose Oxidase / Q000737:chemistry; D006735:Horseradish Peroxidase / Q000737:chemistry; D020100:Hydrogels / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007477:Ions; D028581:Lanthanoid Series Elements / Q000737:chemistry; D057230:Limit of Detection; D008049:Lipase / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry*; D008670:Metals / Q000737:chemistry*; D057139:Nanofibers / Q000737:chemistry*; D055672:Static Electricity; D013696:Temperature; D015032:Zinc / Q000737:chemistry; D000516:alpha-Amylases / Q000737:chemistry
chemical_list: D004800:Enzymes, Immobilized; D005782:Gels; D020100:Hydrogels; D007477:Ions; D028581:Lanthanoid Series Elements; D008670:Metals; D005949:Glucose Oxidase; D006735:Horseradish Peroxidase; D008049:Lipase; D000516:alpha-Amylases; D005947:Glucose; D015032:Zinc