Acetylcholinesterase sensor based on screen-printed carbon electrode modified with prussian blue

Area of Science:

• Electrochemistry
• Biosensors
• Environmental Science

Background:

• Pesticide detection is crucial for food safety and environmental monitoring.
• Acetylcholinesterase (ChE) inhibition is a common mechanism for organophosphorus and carbamic pesticides.
• Development of sensitive and selective sensors is needed for rapid pesticide analysis.

Purpose of the Study:

• To develop and optimize a Prussian blue (PB) modified electrode-based acetylcholinesterase (ChE) sensor.
• To evaluate the sensor's performance for detecting specific organophosphorus and carbamic pesticides.
• To assess the sensor's applicability for monitoring pesticide degradation in complex matrices like wine.

Main Methods:

• Immobilization of electric eel ChE onto a PB-modified screen-printed carbon electrode using glutaraldehyde and BSA.
• Optimization of surface layer components (enzyme activity, Nafion, BSA) for enhanced sensor response.
• Electrochemical detection of thiocholine oxidation mediated by PB at +200 mV in DC mode.

Main Results:

• The developed ChE/PB sensor demonstrated detection limits of 30, 10, and 5 ppb for Aldicarb, Paraoxon, and Parathion-Methyl, respectively (10 min incubation).
• The sensor exhibited high and reliable responses towards substrates and ChE inhibitors after surface layer optimization.
• Feasibility for monitoring pesticide degradation during wine fermentation was demonstrated, although matrix interference reduction methods impacted sensitivity and stability.

Conclusions:

• The ChE/PB sensor offers a sensitive and reliable platform for detecting key organophosphorus and carbamic pesticides.
• The sensor shows potential for real-time monitoring applications, including environmental and food safety analysis.
• Further research is needed to address matrix effects for robust application in complex samples like wine.