Effective electrochemical sensor based on screen-printed electrodes modified with a carbon black - Au nanoparticles composite

A screen-printed electrode (SPE) modified with a carbon black (CB)-Au nanoparticles (AuNPs) compositeis assembled and tested. Electrochemical and morphological investigations highlight the physico-chemical properties of the resulting AuNP-CB-SPE amperometric device with respect to SPEs modifiedwith a single component of the nanocomposite. The effective performance of such a modified elec-trode in activating electrocatalytic processes, consisting both in oxidation and reduction reactions, isdemonstrated. In particular, electrochemical tests on analytes such as glucose, hydrogen peroxide, hydro-quinone, and ascorbic acid, evidence that the composite possesses electrocatalytic performance wellsuperior with respect to the relevant mono-component modified SPE. As a consequence, a meaningfullowering of the peak potentials and improvement of the sensor sensitivities is observed when usingAuNP-CB-SPEs with respect to both CB-SPEs and AuNP-SPEs. In the case of H2O2reduction, the occur-rence of the electrochemical process at less negative potentials is coupled to an improvement of sensorsensitivity of about one order of magnitude. Concurrently, lower limit of detections, ranging from 20 to99% less, have been obtained for the major part of the analytes studied, i.e. glucose, hydrogen peroxideand hydroquinone. Preliminary results reported here indicate that AuNP-CB-SPE can be proposed as anefficient amperometric sensor to be used in many analytical applications.