Polyhedral MgMn₂O₄ oxide nanozyme based for visual detection of epinephrine

Area of Science:

• Materials Science
• Nanotechnology
• Analytical Chemistry

Background:

• Nanozymes mimic natural enzymes, offering tunable properties for various applications.
• Developing efficient catalysts for biosensing remains a key challenge in analytical chemistry.
• Magnesium manganese oxide (MgMn₂O₄) nanozymes present a promising class of materials.

Purpose of the Study:

• To synthesize and characterize polyhedral MgMn₂O₄ nanozymes with tailored morphology and size.
• To investigate the intrinsic oxidase-like catalytic activity of the synthesized nanozymes.
• To develop a sensitive and selective colorimetric sensing platform for epinephrine detection in human urine.

Main Methods:

• Solvothermal synthesis followed by high-temperature calcination to produce MgMn₂O₄ nanozymes.
• Tuning particle size and morphology by adjusting precursor concentration.
• Utilizing the intrinsic oxidase-like activity of nanozymes for catalyzing TMB oxidation.
• Developing a colorimetric sensing platform for epinephrine determination using UV-vis, smartphone RGB/grayscale, and SERS detection.

Main Results:

• Polyhedral MgMn₂O₄ nanozymes with sizes ranging from 1-3 μm were successfully synthesized.
• Optimized nanozymes exhibited significant intrinsic oxidase-like activity, catalyzing TMB oxidation without H₂O₂.
• The developed sensing platform demonstrated a linear detection range of 10-100 μM for epinephrine.
• Achieved low limits of detection (0.289-0.431 μM) across different detection methods.

Conclusions:

• Tailored MgMn₂O₄ nanozymes possess intrinsic oxidase-like activity suitable for biosensing.
• The developed colorimetric sensing platform offers high sensitivity, selectivity, and stability for epinephrine detection.
• This integrated sensing platform shows great potential for practical point-of-care diagnostic applications.