Abiotic sensor for electrochemical determination of chlorpyrifos in natural water based on the inhibition of silver nanoparticles oxidation

Chlorpyrifos, organophosphorus pesticide, is a persistent organic pollutant that may cause serious health problems. Herein, a simple, green, and sensitive electrochemical inhibition sensor based on silver nanoparticles (AgNP)-modified glassy carbon (GC) electrode was developed for the determination of chlorpyrifos in natural water for the first time. The chemical reduction technique based on natural reducing and capping agents such as dissolved organic matter (DOM), natural latex (NL) and mucilage was employed for AgNP synthesis. DOM-AgNP, NL-AgNP, and Mucilage-AgNP were immobilized on GC by sticking technique under the same voltammetric and electrolytic conditions. The oxidation behavior of the three modified electrodes was studied using square wave voltammetry (SWV). DOM-AgNP showed high oxidative dissolution compared to NL-AgNP and Mucilage-AgNP. The three modified electrodes were used for chlorpyrifos determination by the inhibition of AgNP oxidation. The detection limits (LODs) of chlorpyrifos were 48 ?g/L, 30.5 ?g/L, and 17.2 ng/L for DOM-AgNP/GC, NL-AgNP/GC and Mucilage-AgNP sensors, respectively. The three sensors were used for chlorpyrifos determination in natural water with accepted recovery values. AgNP/GC sensor represents a novel abiotic sensor for chlorpyrifos based on the inhibition of the modifier electrochemical response.