Ionic liquid-functionalized graphene for fabricating an amperometric acetylcholinesterase biosensor.

Area of Science:

• Electrochemistry
• Biosensor Technology
• Environmental Science

Background:

• Organophosphate pesticides (OPs) pose significant risks to environmental and human health.
• Existing detection methods for OPs can be complex and time-consuming.
• Development of rapid, sensitive, and reliable detection tools is crucial.

Purpose of the Study:

• To develop a sensitive amperometric biosensor for the detection of organophosphate pesticides (OPs).
• To utilize acetylcholinesterase (AChE) immobilized on ionic liquid-functionalized graphene (IL-G) for enhanced sensor performance.
• To evaluate the biosensor's efficacy using carbaryl as a model OP.

Main Methods:

• Fabrication of a glassy carbon electrode modified with AChE immobilized on IL-G.
• Characterization of the functionalized graphene material for dispersibility and stability.
• Amperometric detection based on the inhibition of AChE enzymatic activity by OPs.
• Quantification of carbaryl using a two-range calibration curve and determination of the limit of detection.

Main Results:

• The biosensor demonstrated high affinity for acetylthiocholine (ATCl) with a K(m) of 0.77 mM.
• Carbaryl detection showed a linear relationship with concentration in the ranges of 0.0025–0.48 and 0.48–1.42 μg mL⁻¹.
• A low detection limit of 0.8 ng mL⁻¹ (S/N = 3) was achieved for carbaryl.
• The developed biosensor exhibited good reproducibility and acceptable stability.

Conclusions:

• The IL-G/AChE/GCE biosensor is a sensitive and reliable platform for organophosphate pesticide detection.
• The biosensor offers a promising tool for the analysis of enzyme inhibitors in various applications.
• This approach provides a new avenue for environmental monitoring and food safety analysis.