Abstract
A simple, rapid and sensitive electrochemiluminescence (ECL) sensor was proposed for direct measurements of methyl parathion (MP) based on the strong affinity of a nano zirconia particles (ZrO2 NPs) modified film on the electrode to the phosphoric group. ZrO2 NPs, which could provide a larger absorption area to immobilize organophosphorus, was firstly modified on the glassy carbon electrode surface to prepare the proposed ECL sensor (ZrO2/GC). Subsequently, the ZrO2/GC electrode was scanned from –0.8 to +0.6 V to obtain the background signal at 0.44 V in a luminol/KCl solution. Then, a certain concentration of MP was added to an aqueous solution for 240 s, which was absorbed onto the ZrO2/GC electrode surface. Moreover, the MP absorbed on the surface of the ZrO2/GC electrode enhanced the ECL signal of luminol in the luminol/KCl solution, which increased with the concentration of MP. As a result, a novel ECL sensor was obtained in a luminol/KCl solution. The MP was determined in the range of from 3.8 × 10−11 to 3.8 × 10−6 mol L−1, with a low detection limit of 1.27 × 10−11 mol L−1 (S/N = 3). The proposed ECL sensor performance for MP detection will open a new field in the application of rapid and screen detection of ultra-trace amounts of organ phosphorus pesticides (OPs) of vegetables used in farm markets.
