Label-free ECL immunosensor for the early diagnosis of rheumatoid arthritis based on asymmetric heterogeneous polyaniline-gold nanomaterial

Abstract Specific and sensitive detection method for anti-cyclic citrullinated peptide antibody (anti-CCP) is highly in demand for the early diagnosis of rheumatoid arthritis (RA). In this work, a label-free electrogenerated chemiluminescence (ECL) immunosensor for the detection of anti-CCP was proposed based on the application of an interfacially synthesized asymmetric heterogeneous nanomaterial. Dumbbell-like polyaniline-gold (PANI-Au) nanocomposite show excellent synergetic enhancement effect on the ECL behaviors of graphite-like carbon nitride (g-C 3 N 4 ). The formation of electrostatic complex between g-C 3 N 4 and PANI-Au composite improves the interfacial stability of hydrophilic g-C 3 N 4. The synergetic enhancement effect of PANI and Au NPs was confirmed by tailoring the morphology of the nanocomposite. An ECL immunosensor was constructed using asymmetric PANI-Au incorporated g-C 3 N 4 as a sensing platform. The presence of Au NPs enables the facile immobilization of the recognition element for anti-CCP antibody. The simple preparation method endows the good reproducibility and stability for the proposed ECL immunosensor. A wide linear range of 0.001 ∼ 15 ng mL −1 with a lower detection limit of 0.2 pg mL −1 was obtained for the determination of anti-CCP antibody. The proposed ECL method may has promising application in other bioassays.