Sensitive riboflavin sensing using silver nanoparticles deposited onto screen-printed electrodes via...

In this work, we elaborated the graphite screen-printed electrodes (SPEs) modification with metal nanoparticles formed as a result of spark discharges produced between a metal wire electrode and SPE that are connected to an Arduino board-based DC high voltage power supply. This sparking device allows, on the one hand, the toposelective formation of NPs of controlled dimensions through a direct and liquid-free approach, and on the other hand, controls the number and energy of the discharges delivered to the electrode surface during a single spark event. This way, the potential damage to the SPE surface by the action of heat evolved during the sparking process is considerably minimized compared with the standard setup in which each spark event consists of multiple electrical discharges. Data demonstrated that the sensing properties of the resulting electrodes are significantly improved compared with those achieved when conventional spark generators are employed, as demonstrated for silver-sparked SPEs that exhibit enhanced sensitivity to riboflavin. Sparked AgNp-SPEs were characterized using scanning electron microscopy and voltammetric measurements in alkaline conditions. The analytical performance of sparked AgNP-SPEs was evaluated by various electrochemical techniques. Under optimum conditions, the detection range for DPV was from 1.9 (LOQ) to 100 nM riboflavin (R2 = 0.997), while a limit of detection (LOD, S/N 3) of 0.56 nM was achieved. The analytical utility is demonstrated for the determination of riboflavin in the real matrices of B-complex pharmaceutical preparation and an energy drink.