Ascorbate Oxidase Mimetic Activity of Copper(II) Oxide Nanoparticles

Area of Science:

• Nanomaterials Science
• Biochemistry
• Analytical Chemistry

Background:

• Oxidase mimetic nanozymes are widely studied, but specific biological substrates like ascorbic acid (AA) are less explored for ascorbate oxidase (AAO) mimics.
• Copper(II) oxide nanoparticles (CuO NPs) present a novel opportunity as AAO mimetic nanozymes.

Purpose of the Study:

• To investigate CuO NPs as ascorbate oxidase (AAO) mimetic nanozymes.
• To develop a fluorescence-based sensor for ascorbic acid (AA) detection utilizing the AAO mimetic activity of CuO NPs.

Main Methods:

• Catalytic oxidation of ascorbic acid (AA) by CuO NPs using dissolved oxygen.
• Kinetic analysis using Michaelis-Menten parameters.
• Development of a fluorescence sensor involving the reaction of dehydroascorbic acid (DHAA) with o-phenylenediamine (OPDA).

Main Results:

• CuO NPs effectively catalyze AA oxidation to DHAA, mimicking AAO activity with comparable Michaelis-Menten constants.
• CuO NPs exhibit superior robustness compared to natural AAO.
• A cost-effective, selective, and sensitive fluorescence sensor for AA was developed with a low detection limit (3.2×10⁻⁸ M).

Conclusions:

• CuO NPs represent a new class of AAO mimetic nanozymes with enhanced stability.
• The developed fluorescence sensor demonstrates significant potential for AA detection in various applications.
• This research expands the utility of oxidase mimetic nanozymes in biology, medicine, and detection science.