Diclofenac determination using CeO2 nanoparticle modified screen-printed electrodes – A study of background correction

Abstract

The detection of low levels of drugs including Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) in natural waters and wastewaters is becoming increasingly important. Electrochemical methods offer an attractive means of detection, as they overcome many disadvantages associated with the currently available analytical methods. Cerium dioxide nanoparticles were synthesised and then incorporated onto the working electrodes of commercial graphite-based Screen Printed Carbon Electrodes (SPCE) then used to determine diclofenac levels. Following initial Cyclic Voltammetry studies, Square Wave Voltammetry (SWV) investigations were conducted over a range of conditions to optimise the peak potential separation and sensitivity of the method. The use of background correction as signal processing is highlighted since it constitutes a mandatory pre-treatment of data before the analysis of results. SWV study was carried out on diclofenac over a concentration range from 0.4 μM up to 26 μM which indicated that the response was linear with a limit of detection of 0.4 μM and a sensitivity of 0.058 μA/μM. The SWV method provides a rapid means of diclofenac detection where cerium dioxide nanoparticles combined with electrode vacuum heat treatment and use of background correction all play an important role.