Genetically engineered acetylcholinesterase-based biosensor for attomolar detection of dichlorvos

Area of Science:

• Biochemistry
• Analytical Chemistry
• Biosensor Technology

Background:

• Acetylcholinesterase (AChE) is a crucial enzyme for nerve function.
• Organophosphate pesticides, like dichlorvos, inhibit AChE activity.
• Developing highly sensitive methods for pesticide detection is vital for environmental and health safety.

Purpose of the Study:

• To design and develop a highly sensitive electrochemical biosensor for dichlorvos detection.
• To utilize a engineered double mutant of Drosophila melanogaster acetylcholinesterase (Dm. AChE) for enhanced sensitivity.
• To achieve attomolar detection limits for dichlorvos.

Main Methods:

• Engineering a double mutant (E69Y Y71D) of Dm. AChE with significantly enhanced dichlorvos inhibition.
• Immobilizing the engineered enzyme onto microporous-activated conductive carbon.
• Developing an inhibitor electrochemical biosensor platform.

Main Results:

• The E69Y Y71D Dm. AChE mutant exhibited a k(i) for dichlorvos 300 times higher than wild-type Dm. AChE.
• The developed biosensor achieved an exceptionally low detection limit of 10(-17) M for dichlorvos.
• This represents a five- to eight-order-of-magnitude improvement over existing biosensors.

Conclusions:

• The engineered Dm. AChE mutant is a highly effective component for ultrasensitive pesticide detection.
• The developed electrochemical biosensor offers a significant advancement in detecting dichlorvos at trace levels.
• This technology holds promise for improved environmental monitoring and toxicological assessments.