Application of graphene for preconcentration and highly sensitive stripping voltammetric analysis of organophosphate pesticide

Electrochemical reduced beta-cyclodextrin dispersed graphene (beta-CD-graphene) was developed as a sorbent for the preconcentration and electrochemical sensing of methyl parathion (MP), a representative nitroaromatic organophosphate pesticide with good redox activity. Benefited from the ultra-large surface area, large delocalized pi-electron system and the superconductivity of beta-CD-graphene, large amount of MP could be extracted on beta-CD-graphene modified electrode via strong pi-pi interaction and exhibited fast accumulation and electron transfer rate. Combined with differential pulse voltammetric analysis, the sensor shows ultra-high sensitivity, good selectivity and fast response. The limit of detection of 0.05 ppb is more than 10 times lower than those obtained from other sorbent based sensors. The method may open up a new possibility for the widespread use of electrochemical sensors for monitoring of ultra-trace OPs. (C) 2011 Elsevier B.V. All rights reserved.