Rhenium Nanoclusters as Modifiers of Immunosensors in the Determination of Tricyclic Antidepressants

The properties of hexarhenium chalcogenide nanoclusters (K 4 [{Re 6 S 8 }(OH) 6 ]·8H 2 O and K 4 [{Re 6 S 8 }(CN) 6 ]·8H 2 O) in combination with carbon nanomaterials (carbon nanotubes and graphene oxide) are studied by voltammetry, electrochemical impedance spectroscopy, atomic force microscopy, and spectrophotometry and their screening is performed for use as hybrid modifiers of screen-printed graphite electrodes in immunosensors in order to improve analytical characteristics. The high negative charge of nanoclusters can be considered the driving force of the adsorption of clusters in the formation of electrodes modified by hybrid nanomaterials. It was found that hexarhenium chalcogenide nanoclusters possess electrochemical activity, which was first used to register immunochemical interactions. The change in the resistance of electron transfer made it possible to choose the best hybrid nanomaterials. The parameters of the surface roughness of the modified electrodes associated with the height properties of the irregularities were estimated. The use of hexarhenium chalcogenide nanoclusters in combination with carbon nanomaterials as hybrid nanomodifiers has made it possible to develop highly sensitive and selective amperometric and impedimetric immunosensors for the determination of tricyclic antidepressants (amitriptyline, desipramine, and imipramine) in pharmaceuticals and urine. The limit of quantification (LOQ) is at the level (4–7) × 10 –11 M. The relative standard deviation does not exceed 5%.