Gold Nanoparticles Electrochemically Deposited on Carbon Nanomaterials and Thiacalixarenes in Immunosensors for Determining Tricyclic Antidepressants

Abstract

Composite materials based on gold nanoparticles electrochemically deposited on a carbon substrate of functionalized graphene oxide, reduced graphene oxide, and carbon nanotube paper in the cyclic voltammetry and chronoamperometry mode are proposed. Screening of composite materials by atomic force microscopy, electrochemical impedance spectroscopy, and voltammetry made it possible to select the best ones as modifiers of planar electrodes, on the basis of which highly sensitive immunosensors are developed. For the best amperometric immunosensors based on a combination of carbon paper, amino(thia)calix[4]arene, and gold nanoparticles, the range of working concentrations for the determination of amitriptyline and desipramine is 1 × 10^–9–1 × 10^–4 M, the limit of quantification is (4–6) × 10^–10 M. Amitriptyline and desipramine are determined by amperometric immunosensors in pharmaceutical preparations with the relative standard deviation no more than 4%. A Comparison of the results of the determination of tricyclic antidepressants in human urine by immunosensors and fluorescence polarization immunoassay with a relative standard deviation no more than 8.5% indicates the accuracy and repeatability of the results obtained.