(Photo)electrochemical characterization of TiO2 Nanocrystals Decorated CVD Graphene based Hybrid

Graphene (G) is an extraordinary structural material for electroanalytical sensors, due to its excellent electrical conductivity, high surface area and mechanical strength. [1] Its potential application in sensors can be extended by a further functionalization with organic and inorganic materials. Here, a solution-based procedure [2] has been implemented, for manufacturing a UV photoactive hybrid material, based on CVD graphene films decorated with UV-light absorbing 1-pyrene butyric acid surface coated TiO2 NCs. The functional properties of the obtained hybrid have been demonstrated by (photo)electrochemical investigations. Cyclic voltammetry profiles have been recorded in presence of an outer- and an inner-sphere probe, namely [Ru(NH3)6]Cl3 and K4[Fe(CN)6], respectively in order to study the electron transfer and the structural properties of the prepared hybrid material based working electrodes. The charge recombination behaviour of the systems has been investigated by studying the transient photocurrent decay that occurs immediately after UV-light illumination. Finally, the devices were tested in the electroanalytical detection of dopamine and norepinephrine, showing promising results. References [1] K.S. Noselov et al., Nature, 490, (2012), 192-200. [2] C. Ingrosso et al., ACS Appl. Mater. & Interfaces, 7, (2015), 4151-4159