An efficient electrochemical sensing platform for profenofos detection

Abstract

Profenofos is classified by the WHO as a moderately toxic pesticide (category II pesticide) for humans as it inhibits the acetylcholinesterase enzyme and causes respiratory distress. In this study, -NaCl-complexed crown ether was used to modify the Glassy Carbon Electrode (GCE) to detect the presence of profenofos in water at ultra-low level concentration. Differential pulse voltammetry was used to detect the target analyte at lower concentration with higher sensitivity. Suppression of charge transfer due to the ionic interaction between the positively charged sodium ion in NaCl-complexed crown ether and the negatively charged oxygen ion in O-ethyl S-propyl phosphorothioate results in the formation of NaCl•15-crown-5-O-ethyl S-propyl phosphorothioate. This in-turn inhibits the charge transfer process of [Fe(CN)6]3-/4-redox couple to the GCE, hence reducing the current density as a function of profenofos concentration. The profenofos sensor exhibits a wide linear range of 1.025–153.645 nM with a low detection limit of 0.341 nM and a sensitivity of 0.05 µA nM−1. And also, the developed sensor showed RSD, % of inhibition, and stability of <2.27%, <5%, 7 days, respectively. Owing to its stability, the sensor can be utilized for real-time testing of water quality.