Application of Molecularly Imprinted Electrochemical Sensor for Selective Non-Labelled Detection of Acetamiprid Insecticide in Fruits

Acetamiprid (ACP) is a widely used systemic insecticide as a replacement for organophosphorus compounds to control sucking-type insects on leafy vegetables, fruits, and tea trees. In this work, bulk polymerized molecularly imprinted polymer was developed using ACP as template, 4-Vinyl pyridine as monomer and ethylene glycol dimethyl acrylate (EGDMA) as cross-linker in presence of acetone as porogen. The polymers were then tested as a template recognition modifiers for carbon paste electrode in cooperation with multiwalled carbon nanotubes as a signal enhancer. The optimum response towards ACP was attained on using 10% of polymer ratio (1: 3: 40) and 5% MW-CNT in the electrode composition at pH 6.2 of 0.1 phosphate buffer as supporting electrolyte. The developed electrode was morphologically and electrochemically characterized and was found to show a linear response for differential pulse voltammetry of 1 × 10 −12 –5 × 10 −6 M equivalent to 0.222–111.3 ×10 4 ng l −1 with limits of detection and quantification of 7.35 × 10 −3 and 0.022 ng l −1 , respectively. The electrode was efficiently applied for ACP detection in its pure solutions, commercial insecticide formulation and spiked apple, tomato, and watermelon samples with recoveries from 95.55%-101.66% indicating its efficiency for application in regulatory units for hazardous food contaminants. An electrochemical sensor was designed nano-level detection of Acetamiprid (ACP). 1:3:40 is the optimum ACP: vinyl pyridine: ethylene glycol dimethacrylate ratio. The sensor showed a good linearity over the 0.222–111.3 × 10 4 ng L −1 . LOD and LOQ of 7.35 × 10 −3 and 0.022 ng L −1 , respectively. ACP was successfully determined in apple, tomato, and watermelon samples.