Improvement of carbon paste-based enzyme electrode using a new ionic liquid [Pmim][PF6] as the binder

Monocrotophos detection with a bienzyme biosensor based on ionic-liquid-modified carbon nanotubes

Acetylcholinesterase (AChE) biosensor technology is widely applied in the detection of organophosphate pesticides in agricultural production via the inhibition of AChE activity by organophosphates. However, the AChE electrode has some drawbacks, such as low stability and high overpotential. Combining the advantages of multiwalled carbon nanotubes (MWCNTs) and ionic liquids, we constructed a novel bienzyme electrode [Cl/iron porphyrin (FePP)-modified MWCNTs/AChE/glassy carbon electrode], which included AChE and mimetic oxidase FePP. In this electrode, FePP is covalently bound to the AChE carrier via ionic liquid for increased electrode sensitivity and stability. Under optimal conditions, this novel biosensor has a monocrotophos detection limit of 3.2 × 10-11 mol/L and good recovery of 89-104%. After 5 weeks of storage at 4 °C, the oxidation current was 97.8% of its original value. The biosensor has high stability and sensitivity for monocrotophos detection and is a promising device for monitoring food safety. Graphical abstract The complete synthesis process of Cl/FePP-MWCNTs/AChE/GCE.

Electrochemical Detection Using Ionic Liquids

Ionic liquids are relatively new additions to the field of electrochemical sensing. Despite that, they have had a significant impact, and several major areas are covered herein. This includes the application of ionic liquids in the quantification of heavy metals, explosives, and chemical warfare agents, and in biosensors and bioanalysis. Also highlighted are the significant advantages ionic liquids inherently have with regards to gas sensors and carbon paste electrodes, by virtue of their non-volatility, inherent conductivity, and diversity of structure and function. Finally, their incorporation with carbon nanomaterials to form various gels, pastes, films, and printed electrodes is also highlighted.