Gold nanoparticles electrochemically deposited on carbon nanomaterials and thiacalixarenes in immunosensors for determining tricyclic antidepressants

Composite materials based on electrochemically deposited gold nanoparticles obtained by cyclic voltammetry and chronoamperometry on a carbon substrate of functionalized graphene oxide, reduced graphene oxide and carbon nanotube paper have been proposed. Composite materials were screened by atomic force microscopy, electrochemical impedance spectroscopy and voltammetry, which allowed us to select the best ones as modifiers of planar electrodes, on the basis of which highly sensitive immunosensors were developed. For the best amperometric immunosensors based on a combination of carbon paper, amino(thia)calix[4]arene, and gold nanoparticles for the determination of amitriptyline and desipramine, the working concentration range was 1 × 10–9–1 × 10–4 M, and the lower limit of detectable concentrations was (4–6) × 10–10 М. Amitriptyline and desipramine were determined by amperometric immunosensors in pharmaceutical preparations with relative standard deviation not exceeding 0.040. Comparison of the results of determination of tricyclic antidepressants by immunosensors and fluorescence polarization immunoassay in human urine with relative standard deviation not exceeding 0.085 indicates the correctness and convergence of the obtained results.