Self-cascade reaction catalyzed by CuO nanoparticle-based dual-functional enzyme mimics

Area of Science:

• Nanomaterials Science
• Biomimetic Chemistry
• Analytical Chemistry

Background:

• Assembling biomimetic properties into catalytic cascades is challenging.
• Cupric oxide nanoparticles (CuO NPs) exhibit oxidase and peroxidase-like activities.

Purpose of the Study:

• To construct a self-organized cascade reaction system using a single CuO NP component.
• To develop a sensitive fluorometric assay for cysteine determination.

Main Methods:

• Investigated CuO NPs as oxidase mimics for cysteine oxidation to cystine and hydrogen peroxide.
• Coupled oxidase activity with CuO NP peroxidase activity for a cascade reaction.
• Utilized terephthalic acid oxidation by hydrogen peroxide for fluorescence generation.

Main Results:

• A single-component nanozyme system was successfully constructed.
• A sensitive fluorometric assay for cysteine was developed with a 6.6 nM detection limit.
• The assay demonstrated satisfactory performance in detecting cysteine in pharmaceutical products and human plasma.

Conclusions:

• Multifunctional CuO NPs can serve as effective enzyme mimics in cascade systems.
• This approach offers a promising route for developing advanced nanozyme-based analytical platforms.
• The study highlights the potential of multifunctional nanomaterials in various applications.