Electrochemical detection of diclofenac and doxorubicin on ZnO/PEO modified screen printed electrodes

Compared to classical analytical methods used for detection of water pollutants, electrochemical sensors have a number of advantages such as sensitivity, selectivity, and repeatability. The detection of commonly used drugs, such as diclofenac and doxorubicin, is important because they are often present as pollutants in water. The aim of this study is to demonstrate that a screen printed electrode modified with zinc oxide and poly(ethylene oxide) (PEO, Mw = 200.000, 600.000 and 900.000 g mol−1) (ZnO/PEO) can be used for the detection of these two drugs. The composite materials ZnO/PEO, with a different molecular mass of PEO (ZnO/PEO-2, ZnO/PEO-6 and ZnO/PEO-9) were synthesized and their structural and morphological characteristics were analyzed. Cyclic voltammetry was applied for the qualitative and quantitative detection of Diclofenac and Doxorubicin. All measurements were performed in phosphate buffer at pH=7, while ZnO/PEO modified C screen printed electrodes were used as the working electrode. We found that prepared electrodes can be used over a wide concentration range, while the detection and quantification limits are low for both drugs.