Inkjet-printed flexible electrochemical sensors based on palladium and silver-decorated, N-doped holey graphene and nano graphene

Inkjet printing is a low-cost method to deposit conductive layers with high precision for electrochemical applications. This work reports the development of flexible electrochemical sensors by inkjet printing of palladium and silver (PdAg)-decorated nitrogen-doped holey graphene and nanographene. Our novel ink formulations were printed on flexible polyethylene tetraflate (PET) substrates to fabricate robust and high-performance flexible electrochemical sensors. The physicochemical properties of the inks, including stability, surface tension, viscosity, and printability, were determined. In addition, the printed electrodes' homogeneity, resistance, and bending resilience were assessed. The electrochemical performance of the electrodes was evaluated against hydrogen peroxide (H2O2) and glucose (Glc). The defective graphene structures had a paramount influence on the ink stability and the ultimate electrochemical performance of the flexible sensors. The sensors showed a low detection limit (LOD) of 3.5 and 0.41 mu M against H2O2 and glucose, respectively, with linear ranges of 0.1-5.6 mM H2O2 and 1-19 mM glucose. Furthermore, the real sample analysis results indicated the applicability of the sensors in real samples.