Amperometric acetylcholinesterase biosensor based on poly (diallyldimethylammonium chloride)/gold nano particles/multi-walled carbon nano tubes-chitosans composite film-modified electrode

作者：Sun Xia^*; Gong Zhili; Cao Yaoyao; Wang Xiangyou

来源：Sensors and Transducers, 2012, 146(11): 78-89.

• Acetylcholinesterase
• AChE activities
• Amperometric
• Amperometric biosensors
• Chlorpyrifos
• Concentration ranges
• Cyclic voltammetric
• Detection limits
• Direct analysis
• Electrochemical response
• Electron transfer
• Film modified electrode
• Glass carbon electrodes
• Gold Nanoparticles
• Layer by layer self assembly
• Linear response
• Loading amount
• Optimized conditions
• Pesticide analysis
• Poly (diallyldimethylammonium chloride)
• Positive charges
• Reproducibilities
• Vegetables and fruits

A novel amperometric biosensor was developed for the detection of organ phosphorus pesticides (OPs). Acetylcholineesterase (AChE) was immobilized onto poly(diallyldimethylammonium chloride) (PDDA)/gold nano particles (AuNPs)/multi-walled carbon nanotubes-chitosans (MWCNTs-CHIT) composite film modified glass carbon electrode (GCE). The biosensor had good sensitivity owing to the excellent properties of MWCNTs and AuNPs, which promoted electron transfer and improved the electrochemical response. PDDA with positive charge was bound electrostatically to AChE with negatively charge by layer-by-layer (LbL) self-assembly technique, which can increase AChE loading amount. The morphologies and the sensitive steps of surface modification were characterized by scanning electron microscopy (SEM), cyclic voltammetric (CV) and electrochemical impedance spectroscopy (EIS), respectively. Based on the inhibition of OPs on the AChE activity, under the optimized conditions, the biosensor exhibited a linear response to chlorpyrifos in the concentration range from 0.8 to 20 μg/L and from 20 to 300 μg/L, with a detection limit of 0.56 μg/L. The biosensor exhibited good reproducibility and acceptable stability. Moreover, PDDA-AChE/AuNPs/MWCNTs-CHIT/GCE biosensor can also be used for direct analysis of practical samples, which may open a new door for pesticide analysis in vegetables and fruits.

• 出版日期2012
• 单位山东大学