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

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 (R) 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 mono-mer), 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 mu g/mL, with LOD and LOQ of 0.1 pg/mL and 0.3 pg/mL, respectively.

Automated summary

Metribuzin, an important herbicide widely used in fields, was detected using an electrochemical sensor with good selectivity and sensitivity. The sensor showed a linear response over a wide concentration range and achieved successful detection in commercial products and samples.