Application of molecularly imprinted electrochemical sensor for trace analysis of Metribuzin herbicide in food samples

• Published in: Food chemistry 2023-03, Vol.404, p.134708-134708, Article 134708
• Main Authors: Atef Abdel Fatah, Mohamed, Abd El-Moghny, Muhammad G., El-Deab, Mohamed S., Mohamed El Nashar, Rasha
• Format: Article
• Language: English
• Subjects: Bulk polymerization; Differential pulse voltammetry; Herbicide; Metribuzin; Molecularly imprinted polymers
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2022.134708

•MIP electrochemical sensor is designed for nano-level detection of Metribuzin (MTZ).•The optimum composition of MIP (MTZ: ItA: EGDMA) is 1:5:30.•The sensor shows a good linearity over the range 0.2 ng/mL to 21.429 µg/mL.•The sensor exhibits LOD of 0.1 pg/mL and LOQ of 0.3 pg/mL.•MTZ’ sensor was applied for tomatoes, potatoes, and Egyscor® 70% herbicide. Metribuzin (MTZ) is an important herbicide widely used in fields and represents a big threat to the environment and health. Herein, an electrochemical sensor was designed for its detection in commercial product (Egyscor® 70%), spiked tomatoes and potatoes samples with recovery values ranging from 97.12 to 103.41%. Bulk-polymerized MTZ molecularly imprinted polymer (MIP) was developed, using itaconic acid (functional monomer), ethylene glycol dimethacrylate (cross-linker) at an optimum molar ratio 1:5:30, respectively. Differential pulse voltammetry was used to examine the optimization variables of the MIP based sensor such as the variation of (template: monomer: cross-linker) ratio, accumulation time, multi walled carbon nanotubes amount, pH and scan rate, while cyclic voltammetry and electrochemical impedance spectroscopy were used to characterize the sensor. The sensor showed selective adsorption ability and a good linearity over the concentration range of 0.2 ng/mL to 21.429 µg/mL, with LOD and LOQ of 0.1 pg/mL and 0.3 pg/mL, respectively.