Detection of chlorpyrifos via carbon nanotubes and AuPd nanoparticles-enhanced MXene electrode-based acetylcholinesterase biosensor

Abstract

An ultra-sensitive and high-efficient acetylcholinesterase (AChE) electrochemical sensing platform on the basis of MXene/carbon nanotubes (CNTs) and Au-Pd composites was constructed for the rapid detection of chlorpyrifos. Negative CNTs modified with cationic surfactant cetyltrimethylammonium bromide were self-assembled on MXene through the electrostatic interaction. The introduction of CNTs and AuPd nanoparticles reduced the stacking of MXene layers and increased the utilization of specific surface area to load AChE. The MXene/CNTs/AuPd-based glassy carbon electrode (GCE) exhibited relatively lower electrochemical impedance compared with other materials. The prepared MXene/CNTs/AuPd-AChE/GCE-based electrochemical method possessed high repeatability, reproducibility, and anti-interference ability. The linear range for detecting chlorpyrifos was 2.85 × 10−12–2.85 × 10−6 M and the limit of detection was 1.98 pM. Finally, the established method was successfully used to detect chlorpyrifos in spinach and orange and recoveries were ranging from 93.68 % to 104.21 %, which presented the great potential for quantitatively analyzing of organophosphorus pesticides in food samples.