Highly sensitive fipronil pesticide detection on ilmenite (FeO•TiO2)-carbon paste composite electrode

Ilmenite (FeO center dot TiO2) has been widely known as an excellent catalyst in antimicrobial activity, chemical oxygen demand (COD) sensing, photocatalysis and photoelectrocatalysis. Here we report the role of ilmenite in electrochemical detection of fipronil pesticide using ilmenite modified carbon paste electrode. It was found that the ilmenite effectively enhanced the electrochemical sensing of CPE electrode towards the presence of fipronil pesticide compound in 1.0 M MgSO4 electrolyte solution with a strong anodic current (160 mu A) at the oxidation potential of -0.4 V, which is related to the electron releasing from the compound. The limit of the detection (LOD) and Horwitz Ratio (HR) values were calculated to be as low as 0.0012 mu M and 0.173%. The electrode also demonstrates high stability with life-time usage can be up to 24 days of repeated used. The new ilmenite-CPE electrode is also able to detect the presence of fipronil under a high concentration of Cu2+ ion, inferring a high selectivity property. The electrode preparation and the sensing characterization will be discussed in details.