Enzyme-Loaded Hemin/G-Quadruplex-Modified ZIF-90 Metal–Organic Framework Nanoparticles: Bioreactor Nanozymes for the Cascaded Oxidation of N-hydroxy-l-arginine and Sensing Applications

Chaochao Chen, Margarita Vázquez-González, Michael P. O'Hagan, Yu Ouyang, Zhanhui Wang*, Itamar Willner*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

48 Scopus citations

Abstract

Biocatalytic cascades are challenging to operate in homogeneous solution, where diffusional mass transport hinders efficient communication between the reactive components. There is great interest in developing devices to perform such transformations in confined environments, which increase the efficiency of the cascaded process by generating high local concentrations of the reactive species. Herein, a bioreactor-nanozyme assembly is introduced for the cascaded aerobic oxidation of N-hydroxy-l-arginine (NOHA) to citrulline in the presence of glucose. The reaction mimics a key step in the nitric oxide synthase oxidation of l-arginine in nature. The system consists of glucose oxidase (GOx)-loaded hemin/G-quadruplex (hemin/G4)-modified ZIF-90 metal–organic framework nanoparticles. The aerobic oxidation of glucose by GOx yields H2O2 that fuels the hemin/G4-catalyzed oxidation of NOHA into citrulline. The process driven by the bioreactor-nanozyme system is ≈sixfold enhanced compared to the homogeneous mixture of the biocatalysts, due to its operation in the confined environment of the nanoparticles. Extension to a three-step cascade is then demonstrated using a bioreactor composed of β-galactosidase/GOx-loaded hemin/G4-modified ZIF-90 nanoparticles activating the cascaded oxidation of NOHA to citrulline, in the presence of lactose. Moreover, the bioreactor-nanozyme hybrid is applied as a functional optical sensor of glucose, using fluorescence or chemiluminescence as readout signals.

Original languageEnglish
Article number2104420
JournalSmall
Volume18
Issue number11
DOIs
StatePublished - 17 Mar 2022

Bibliographical note

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© 2022 Wiley-VCH GmbH

Keywords

  • biocatalytic cascades
  • chemiluminescence
  • DNA nanotechnology
  • DNAzymes
  • nitric oxide
  • sensors

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