Direct Electrochemical Determination of Methyl Jasmonate in Wheat Spike let at a Nano-Montmorillonite Film Modified Electrode by Derivative Square Wave Voltammetry

The direct electrochemical determination of methyl jasmonate (MeJA) at a nano-montmorillonite modified glassy carbon electrode (nano-MMT/GCE) is reported. The modified electrode, prepared by a simple casting drying method and characterized by scanning electron microscope (SEM) and electrochemical impedance spectra (EIS), was proved to process a uniform nanostructured surface with a large surface area and a fast electron transfer rate. This electrode exhibited a sensitive electrochemical response for the direct oxidation of MeJA in 0.1 mol L-1 HClO4, which could be further improved by using a derivative square wave voltammetry technique. Thus, a simple and fast electrochemical method for the determination of MeJA is proposed. Under optimal working conditions, the oxidation current of MeJA linearly increased with its concentration in the range of 7.0 x 10(-7)-1.0 x 10(-3) mol L-1 with a detection limit of 5.0 x 10(-7) mol L-1. This method had been applied to the determination of MeJA content in wheat spikelet samples.