Simultaneous detection of monocrotophos and dichlorvos in orange samples using acetylcholinesterase-zinc oxide modified platinum electrode with linear regression calibration

Monocrotophos (MCP) and dichlorvos (DDVP) belong to the group of organophosphate pesticides and are categorized as highly toxic by the World Health Organization. Consumption of oranges containing MCP and DDVP leads to harmful health effects such as DNA damage, apoptosis, cardiotoxicity and cancer. It also causes chronic disorders such as eye irritation, miosis, blurred vision; dizziness, convulsions, dyspnea salivation, abdominal cramps, nausea, diarrhea and vomiting. In this context, an acetylcholinesterase modified Pt working electrode for the simultaneous detection of MCP and DDVP in orange samples was fabricated using zinc oxide nanospheres as a nano-interface. An analytical method for the simultaneous detection of MCP and DDVP was constructed by establishing 24 linear regression models and error analysis was performed to verify the practicability of these models. The developed biosensor achieved a detection limit of MCP and DDVP with detection limits of 0.036 and 0.012 nM respectively. AChE enzyme was successfully reactivated using 2-pyridine aldoxime methiodide. The developed biosensor exhibited good recovery, thus providing a promising tool for analysis of MCP and DDVP. (C) 2016 Elsevier B.V. All rights reserved.