Investigation on morphologies and supporter of cerium dioxide nanostructure on oxime based electrochemical sensors for organophosphorus detection

Pralidoxime (PAM) chloride has been taken as be an effective electrochemical probe to detect organophosphorus pesticides (OPs). In our previous work, CeO 2 nanoparticles were proved to be able to significantly improve the sensitivity of the as-fabricated electrochemical sensor. In this paper, PAM-based sensors with different morphologies and supporters of nano-structured CeO 2 were investigated. Firstly, CeO 2 particles, CeO 2 cubes and CeO 2 rods were prepared and characterized. The results show that the CeO 2 rods exhibits the best electrochemical performance because of its larger specific surface and better electrocatalytic activity. Secondly, multi-walled carbon nanotubes (MWCNTs), carbon powder (CP) and Carbon aerogel (CA) were adopted as supporter to disperse CeO 2 rods. The results show that CA with large specific surface area and excellent adsorption property makes the fabricated sensor exhibit the best performance. Under the optimized conditions, the sensor has a chlorpyrifos detecting limit of 3.4 × 10 −12  M in the range from 5 × 10 −11  M to 1 × 10 −7  M. Besides, the sensor also shows good repeatability, stability and reliability in the detection of chlorpyrifos.