Metal-organic framework-based multienzyme cascade bioreactor for sensitive detection of methyl parathion

Area of Science:

• Materials Science
• Biotechnology
• Analytical Chemistry

Background:

• Methyl parathion (MP) is a hazardous organophosphate pesticide found in food.
• Sensitive and reliable detection methods for MP are crucial for food safety.
• Existing detection methods may lack sensitivity or require complex procedures.

Purpose of the Study:

• To develop a highly sensitive cascade nanobioreactor for detecting methyl parathion (MP) in food samples.
• To enhance enzyme stability and catalytic efficiency using a zeolitic imidazole ester backbone (ZIF-8).
• To create a fluorescence-based detection system utilizing gold nanoclusters.

Main Methods:

• Simultaneous encapsulation of acetylcholinesterase (AChE) and choline oxidase (CHO) within ZIF-8.
• Encapsulation of glutathione-stabilized gold nanoclusters (GSH-AuNCs) in ZIF-8 via ligand self-assembly.
• Utilizing the cascade reaction of AChE/CHO and Fe(II) to generate hydroxyl radicals (·OH) that quench GSH-AuNCs fluorescence.

Main Results:

• The nanobioreactor demonstrated high stability and cascade catalytic efficiency.
• The system achieved a low limit of detection for MP at 0.23 µg/L.
• MP inhibition of AChE activity led to fluorescence restoration, enabling quantitative detection.

Conclusions:

• The developed MOF-based cascade nanobioreactor provides a sensitive platform for MP detection.
• This approach offers a promising strategy for the analysis of trace hazards in food.
• The nanobioreactor design enhances enzyme performance and fluorescence-based sensing capabilities.