Graphene modified screen printed immunosensor for highly sensitive detection of parathion

Area of Science:

• Environmental Science
• Analytical Chemistry
• Biosensor Technology

Background:

• Indiscriminate pesticide use necessitates sensitive detection methods for contaminants in food and water.
• Parathion, an acetylcholinesterase inhibitor, is a widely used pesticide with diverse toxic effects.
• Existing detection methods require improvement for sensitivity and specificity.

Purpose of the Study:

• To fabricate and evaluate a graphene-based impedimetric immunosensor for sensitive and specific parathion detection.
• To establish the sensor's performance characteristics, including linear range, limit of detection, and selectivity.
• To validate the sensor's applicability in real-world samples.

Main Methods:

• Screen-printed carbon electrodes (SPEs) were modified with graphene sheets.
• Electrochemical functionalization of graphene with 2-aminobenzyl amine (2-ABA).
• Immobilization of anti-parathion antibodies onto the functionalized graphene surface.
• Impedimetric detection of parathion.

Main Results:

• The developed immunosensor demonstrated a broad linear detection range for parathion (0.1–1000 ng/L).
• Achieved a very low limit of detection (LOD) of 52 pg/L for parathion.
• Exhibited high selectivity for parathion against other common pesticides like malathion, paraoxon, and fenitrothion.
• Successfully detected parathion in real food samples (tomato, carrot) and showed good correlation with HPLC analysis.

Conclusions:

• The fabricated graphene-based impedimetric immunosensor is highly sensitive and selective for parathion detection.
• This biosensor shows significant potential for monitoring parathion contamination in food and environmental samples.
• The developed sensor offers a viable alternative for pesticide residue analysis.