Electrochemical nanobiosensor for early detection of rheumatoid arthritis biomarker: Anti- cyclic citrullinated peptide antibodies based on polyaniline (PANI)/MoS2-modified screen-printed electrode with PANI-Au nanomatrix-based signal amplification

Anti-cyclic citrullinated peptide (aCCP) antibodies are predictive biomarker tools for early detection of rheumatoid arthritis. In this study, square wave voltammetry (SWV) electrochemical aCCP immunosensor was fabricated using molybdenum disulfide (MoS2) polyaniline (PANI) as the base matrix of the screen-printed electrode (SPE) while employing an interfacial polymerized PANI-gold (Au) nanomatrix to entrap the aCCP antibodies with higher signal amplification. The modified electrode was characterized morphologically by Scanning electron microscopy, Transmission electron microscopy, X-ray photoelectron spectroscopy, Fourier-transform-Infrared spectroscopy (FT-IR), UV-vis spectroscopy, X-ray diffraction and electrochemically by Electrochemical impedance spectroscopy, Cyclic voltammetry and Square wave voltammetry. The sensor performance was investigated in 1X phosphate-buffered saline (PBS) and human serum (10 % HS), where the obtained limit of detection values was 0.16 IU/mL (PBS) and 0.22 IU/mL (10 % HS) with logarithmic linearity between 0.25 and 1500.0 IU/mL of aCCP. The sensor showed selectivity, storage stability (7.7 % lost after 4 weeks), repeatability (3.32 % RSD) and reproducibility (3.49 % RSD). The immunosensor was also applied to real-time aCCP detection in aCCP-spiked HS.

Automated summary

The study successfully developed an electrochemical aCCP immunosensor using SWV, demonstrating early detection of aCCP antibodies. The sensor showed high selectivity, stability, and good linear relationship within different concentration ranges.