Facile Synthesis of Ordered Mesoporous Zirconia for Electrochemical Enrichment and Detection of Organophosphorus Pesticides

Abstract

AbstractHighly crystallized mesoporous ZrO2 nanomaterials were synthesized by solvent evaporation induced self‐assembly approach. Ordered mesoporous ZrO2 nanomaterials were characterized by TEM, SEM, BET, XRD and UV‐Vis spectroscopy. The obtained nanomaterials exhibit the close‐packing mesopores with average pore size of 7 nm and a highly crystallized framework with tetragonal phase. A non‐enzyme electrochemical sensor based on ordered mesoporous ZrO2 is established for selective detection of methyl parathion (MP). The online extraction of MP is firstly achieved by ZrO2 modified electrode at open‐circuit potential for 5 min., and the sensitive detection of MP is performed by differential pulse voltammetry (DPV) method. By comparison, DPV responses of mesoporous ZrO2 are 40 times and 25 times larger than that of mesoporous silica and mesoporous carbon with the similar pore structure, implying the specific affinity advantage of zirconia to phosphoric group. The quantitative analysis result shows that the voltammetric currents are linear with concentrations of MP ranging from 1 ng/ml to 2 μg/ml with a detection limit of 0.53 ng/ml. The sensor also exhibits good stability and high selectivity against interfering species. The excellent analytical performances are owed to the accessible and uniform mesoporous structures, highly crystallized frameworks of ZrO2 and its specific affinity to phosphate groups.