Electrochemical Sensors Based on Manganese and Cobalt Oxide Nanostructures for the Detection of Flutamide and its Derivatives in Real Water Samples

Flutamide (FLU), bicalutamide (BIC), and hydroxyflutamide (OHF), having a low biodegradability, may cause severe health effects on humans as antiandrogens. In this work, we have developed two electrochemical sensors using manganese oxide (MnO) and Cobalt oxide (CoO) nanostructures (NSs) as electrocatalysts. The GCE modified with MnO is referred to as MnO/GCE and the GCE modified by CoO is referred to as CoO/GCE. The electrochemical behaviours of CoO/GCE and MnO/GCE were examined in ferricyanide solution. It was observed through the employment of cyclic voltammetry that MnO/GCE exhibit better electron transfer than CoO/GCE. The calculated surface coverage values, 1.46 x10 −9 mol cm −2 and 5.02 x10 −9 mol cm −2 of MnO/GCE and CoO/GCE suggest a multilayer of a metal oxide molecule film at the surfaces of glassy carbon electrodes (GCE). FLU, BIC and OHF were detected at a linear range from 32.01 to 50.00 µM. The limits of detection of FLU, BIC and OHF were 18.5, 13.0 and 78.8 µM at MnO/GCE respectively and 18.8, 18.7 and 18.5 µM at CoO/GCE respectively. Both MnO/GCE and CoO/GCE showed good catalytic stability towards detecting FLU and its derivatives. FLU, BIC and OHF were also detected in the presence of interferents for both electrochemical sensors in phosphate buffer solution. Both MnO/GCE and CoO/GCE confirmed good selectivity without cross interference. Some of the health effects associated with FLU, BIC and OHF are liver damage, prostate inflammation, and methamoglobenia. Although FLU, BIC and OHF are detected in low concentration levels in water bodies, their continuous ingestion is a great concern. As far as we know, MnO and CoO NSs have not been used to electrochemically detect FLU, BIC and OHF. Furthermore, OHF has not been detected electrochemically before and there are only a few studies on the electrochemical detection of BIC. Hence, MnO and CoO NSs are used in this study for the first time for an electrochemical sensor fabrication towards the detection of FLU, BIC and OHF.