Reduced Graphene Oxide, Nanodiamonds, and Hexarhenium Chalcogenide Clusters Incorporated into Amperometric Immunosensors for the Determination of Desipramine

Abstract

The present work introduces nanocomposites based on carbon materials of various nature and hexarhenium chalcogenide clusters as surface modifiers of screen-printed graphite electrodes for amperometric immunosensing of the tricyclic antidepressant desipramine. The surface modification of the electrodes by chronoamperometric reduced graphene oxide in combination with chalcogenide hexarhenium clusters or nanodiamonds was developed for the determination of desipramine. The properties of the nanocomposites studied by voltammetry and electrochemical impedance spectroscopy (EIS) were correlated with the roughness parameters of their modified surface associated with the height properties of the irregularities estimated by atomic force microscopy. The composition of the hybrid nanostructures was optimized to provide the following analytical figures of merit for the immunosensors: the range of working concentrations from 1 × 10−4 to 1 × 10−9 М and the lower limit of the determined concentrations of (5–8) × 10−10 М. The optimal parameters for sequential injection analysis were obtained at a flow rate of 25 µl s−1 and the injected volume of 3125 µl of the supporting buffer at pH 7.5. It is possible to determine lower concentrations of desipramine equal to (7–9) × 10−11 M using the proposed immunosensors in the flow mode. The testing of the developed immunosensors was characterized by the determination of the analyte in a pharmaceutical preparation and in urine. The relative standard deviation was less than 0.072.