Impact of cleaning procedures on screen-printed gold electrodes performance for mutation detection

Abstract The manufacture of biosensors has significantly increased in the field of biomedicine, driven by their miniaturization and portability. However, the quality of the obtained results can be compromised by potential inconsistencies on the electrode surface arising from manufacturing defects and necessary pre-treatments before use. This study evaluated four cleaning methods for screen-printed gold electrodes (SPGEs): HClO 4 , H 2 O 2 (electrochemical and chemical agent exposure methods). The electrodes were characterized by cyclic voltammetry (CV), differential pulse voltammetry (DPV), and high-resolution scanning electron microscopy (SEM) at magnifications of ×5000, ×20,000, and ×50,000. After comparing the results, the most effective pretreatment was selected. Furthermore, a final comparison was conducted to assess the capacity for depositing a genetic mutation of the K-ras gene, before and after applying the selected cleaning method. The results indicated that the untreated electrodes were not uniform and exhibited surface interference, detected by SEM as dark spots. These interferences were effectively eliminated by an electrochemical cleaning method, complemented by CV with [Fe(CN) 6 ] 3 −/ 4 −, which also stabilized the electrode surface, allowing for the correct deposition of the DNA probes. Graphical abstract