Carbon based Nanomaterials combined with β-Cyclodextrin and Ferrocenyl-Carnosine for Electrochemical Sensing

Miniaturized electrochemical sensors, which possess highly sensitive and selective detection capabilities for specific analytes, hold promise for achieving rapid responses under easily accessible and cost-effective operating conditions. Modifying electrode surfaces using appropriate carbon-based nanomaterials enables the immobilization of recognition elements and enhances electrical conductivity, ultimately improving the sensitivity of the sensors [1,2]. We have developed nanohybrid systems by combining carbon-based nanomaterials (CBNs) such as graphene (G) and carbon nanotubes (CNTs) with β-cyclodextrin (CD) for the modification of Screen-Printed Carbon Electrodes (SPCEs). The cyclodextrin decorated CBNs were tested for the modification of SPCE surfaces using FcCAR ligand (i.e. carnosine modified with ferrocene) having sensing ability toward toxic heavy ions, as model probe [3-4]. As increasing the CNT-CD or GCD layering on the SPCE, signal amplification was observed due to the deposition of carbon-based conductive material that induces capacitive behavior on the electrode surface. The functionalized CBNs were characterized by several techniques, including TGA, micro-Raman, SEM, and XPS analyses. The analytical performances of SPCEs modified with CNT-CD or GCD were studied by different techniques including electrochemical impedance spectroscopy, chronoamperometry and differential pulsed voltammetry. The results obtained in our studies, compared with the most recent papers using modified SPCE, highlight the importance of nanohybrid systems, which not only combine the properties/characteristics of the starting components ones, but also give rise to new properties due to the synergic actions of the native ones and, therefore, able to increase electrochemical response and to facilitate the grafting of the recognition element on electrode surface. [1].Ostertag, B. J.; Cryan, M. T.; et al. ACS Appl. Nano Mater. 2022, 5, 2241−2249. [2].Hatamie, A.; Rahmati, R.; et al. ACS Appl. Nano Mater. 2019, 2, 2212−2221. [3].Mazzaglia, A.; Scala, A.; et al. Colloids Surf., B 2018, 163, 55−63. [4] Piperno, A.; Mazzaglia, A.; et al. ACS Appl. Mater. Interfaces 2019, 11, 46101−46111. [5] Abate, C.; Neri, G.; et al. ACS Appl. Nano Mater. 2023, 6, 17187–17195. ACKNOWLEDGMENTS This work has been partially funded by European Union (NextGeneration EU), through the MUR-PNRR project SAMOTHRACE (ECS00000022).