Electrochemical immunosensor based on carbon nanofibers and gold nanoparticles for detecting anti-Toxoplasma gondii IgG antibodies

• Published in: Mikrochimica acta (1966) 2023-09, Vol.190 (9), p.367-367, Article 367
• Main Authors: Salimi, Mahboobeh, Keshavarz-Valian, Hossein, Mohebali, Mahdi, Geravand, Mahvash, Adabi, Mahdi, Shojaee, Saeedeh
• Format: Article
• Language: English
• Subjects: Analytical Chemistry; Antibodies; Antigens; Carbon fibers; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Electric properties; Electrochemical analysis; Electrodes; Enzyme-linked immunosorbent assay; Enzymes; Field emission microscopy; Immunoglobulin G; Immunosensors; Microengineering; Nanochemistry; Nanofibers; Nanoparticles; Nanotechnology; Original Paper; Peroxidase; Protozoa; Raman spectroscopy; Reproducibility; Spectrum analysis; Toxoplasmosis; Voltammetry
• ISSN: 0026-3672; 1436-5073
• DOI: 10.1007/s00604-023-05928-3

An electrochemical immunosensor based on carbon nanofibers (CNFs) and gold nanoparticles (AuNPs) was developed for detecting anti- Toxoplasma gondii antibodies  (anti- T. gondii ) IgG in human serum. CNFs were produced using electrospinning and carbonization processes. Screen-printed carbon electrode (SPCE) surface was modified with CNFs and AuNPs which were electrodeposited onto the CNFs. Then, T. gondii antigen was immobilized onto the AuNPs/CNFs/SPCE. Afterward, anti- T. gondii IgG positive serum samples were coated on the modified electrode and assessed via adding anti-human IgG labeled with horseradish peroxidase (HRP) enzyme. The morphology of SPCE, CNFs, and AuNPs/CNFs/SPCE surface was characterized using field emission scanning electron microscopy (FESEM) equipped with energy dispersive spectroscopy (EDS). Characterization of CNFs was evaluated by Raman spectroscopy and X-ray diffraction (XRD). Electrochemical characterization of the immunosensor was verified using cyclic voltammetry (CV), and electrochemical response of modified electrode for anti- T. gondii IgG was detected via differential pulse voltammetry (DPV). This immunosensor was detected in the range 0–200 U mL −1 with a low detection limit (9 × 10 −3 U mL −1 ). In addition, the proposed immunosensor was exhibited with high selectivity, strong stability, and acceptable reproducibility and repeatability. Furthermore, there was a strong correlation between results obtained via the designed immunosensor and enzyme-linked immunosorbent assay (ELISA) as gold standard. In conclusion, the developed immunosensor is a promising route for rapid and accurate clinical diagnosis of toxoplasmosis. Graphical abstract