A photothermal assisted in situ signal-amplified electrochemical immunoassay based on multifunctional probe for detecting autoimmune hepatitis marker

Abstract

Herein, a photothermal in-situ amplified electrochemical immunoassay based on multifunctional probe for detecting autoimmune hepatitis marker was constructed. The immunoassay followed a sandwich protocol, helical carbon nanotubes (HCNTs) and polyaniline (PANI) composite provided a desirable substrate for the immobilization of massive primary antibody (Ab1). Subsequently, the multifunctional probe, by utilizing Chitosan (CS) modified AgI nanohybrids (AgI NHs) labeled secondary antibody (Ab2), were simply designed for the first time. To be specific, AgI NHs were not only directly served as signal readout, but also as amplifier further enhanced electrochemical signal. Under the near-infrared (NIR) laser irradiation, electrochemical reaction was significantly accelerated on electrode in situ due to the extraordinary photothermal conversion capability of AgI NHs. Therefore, the evidently improved sensitivity together with enhanced signal-to-noise ratio of immunoassay was achieved in the short time by precise-controlling of NIR laser irradiation. Under the optimal conditions, the developed electrochemical immunoassay realized sensitive and specific detection of autoimmune hepatitis marker from 10−4 ng/mL to 1 ng/mL with low detection limit of 3.3 × 10-5 ng/mL. Importantly, this work provided a promising prospect for the application of photothermal effect coupled with electrochemical immunoassay and opened up a new pathway for signal amplification.