Development of square wave voltammetry method using working electrodes modified with nickel oxide and carbon black for determination of 5-hydroxymethylfurfural in honey

This work describes the development of a novel square wave voltammetry (SWV) method for the rapid and sensitive quantification of 5-hydroxymethylfurfural (HMF) in honey samples. The method employs a combination of nickel oxide and carbon black (NiO-CB) to modify lab-made screen-printed carbon electrodes (SPCEs). The adaptability of the NiO-CB/SPCE enables its potential application in detecting HMF based on electrochemical reduction, which eliminates the need for sample extraction and streamlines the analysis process. The developed SWV method exhibits suitable working ranges of 0.5-10.0 mg kg-1 for HMF in the buffer and 10.0-200.0 mg kg- 1 for HMF in honey, achieving accurate and precise measurements with a limit of detection (LOD) and limit of quantification (LOQ) of 5.4 and 18.0 mg kg- 1, respectively. The exceptional specificity of the developed method towards HMF is confirmed by its negligible response to interfering substances commonly found in honey. Furthermore, a comparative study between the developed SWV and the standard highperformance liquid chromatography (HPLC) methods reveals a strong correlation and no significant difference in the results obtained. Hence, the innovative electrochemical method can be utilized as an alternative method for rapidly quantifying HMF in honey samples.