Nafion mixed carbon nanotube modified screen-printed carbon electrode as a disposable electrochemical sensor for quantification of Amitraz in honey and longan samples

Abstract

Amitraz, (N'-(2,4-dimethyl phenyl)-N-[(2,4-dimethyl phenyl)iminomethyl]-N-methylmethanimidamide) is a broad-spectrum acaricide used in veterinary medicine and agriculture. Herein, a sensitive electrochemical method has been successfully developed to quantify Amitraz exploiting CNT (carbon nanotube) and Nafion (a conductive polymer) for modifying a homemade working electrode of screen-printed carbon electrode (SPCE). The amount ratio of CNT and Nafion, pH of supporting electrolyte, accumulation time, and square wave voltammetric (SWV) conditions were optimized to enhance the sensitivity of the electrochemical sensor. The linear response of the developed sensor ranges from 0.005 to 1.00 µg mL−1 with a limit of detection (LOD) of 1.0 ng mL−1 and a limit of quantification (LOQ) of 20 ng mL−1, which is significantly lower than maximum residue levels (MRLs) of Amitraz in honey and longan. The developed method has been successfully applied to determine Amitraz concentrations in honey and longan samples. Obtained recoveries are in the range of 80–110%, with a relative standard deviation (RSD) lower than 10%, indicating that it can be used to quantify Amitraz in real samples. Moreover, the electrochemical sensor based on the modified CNT/Nafion/SPCE expounds high sensitivity, simplicity, and cost-effectiveness.