Nanomaterials-modified screen-printed electrodes: a powerful platform for sensor and biosensor set-up.

The use of nanomaterials in sensor and biosensor field is one of the hottest topics today in analytical chemistry. The advantage of using nanomaterials leads to sensors characterized by high sensitivity, stability, and an improved repeatability1. Screen-printed electrodes (SPEs) are recognized as successful sensor platforms in modern electroanalytical chemistry due to their low background, wide potential window, cost-effectiveness, and easiness of surface modification. This last property allows modifying the screen-printed electrodes (SPEs) with several nanomaterials such as carbon nanotubes, graphene, nanoparticles, graphene nanoplates (GNPs)2, etc3,4. In this work, a comparative study using these devices (SPEs) modified with different nanomaterials via drop-casting procedure is reported (Figure 1). Moreover, the modified SPEs have been morphologically and electrochemically characterized. The research activity carried out for the development of sensors and biosensors based on SPEs modified with nanomaterials will be presented. Among the different feasible applications, the use of these nano-engineered biosensors for uric acid quantification based on SPEs modified with carbon nanotubes (bare or functionalized) and graphene nanoplatelets (GNPs) will be introduced. Significant improvements in analytical parameters have been obtained, when using nano-modified SPEs with respect to biosensors based on bare SPEs. Limit of detection (LOD), linear range and Km (Michaelis-Menten Constant) undergo remarkable ameliorations (LOD going from 48 μM to 12 μM, linear range from 0.05-2 mM to 0.02-5 mM and Km from 0.43 to 1.31 mM for bare and -CO2H MWNT based biosensors, respectively). Figure1 Schematic representation of nanomaterial-modified SPE: a) by drop casting and then used to set up a biosensor, b) enzyme immobilization. Electrochemical measurements can be performed using portable instrumentation (c)