A competitive electrochemical immunosensor based on bimetallic nanoparticle decorated nanoflower-like MnO_2 for enhanced peroxidase-like activity and sensitive detection of Tetrabromobisphenol A

摘要

In this work, a novel competitive electrochemical immunosensor was developed based on gold palladium bimetallic nanoparticles which were successfully synthesized and modified by amine (-NH_2) functionalized-nanoflower-like manganese oxide (NH_2-fMnO_2) for the rapid and sensitive detection of TBBPA in environmental waters. The MWCNTs modified GCE was employed to load TBBPA-antigens (Ag) through the effects of adsorption for the design of a highly sensitive immunosensor, which provided a large surface area for the specific recognition between antigen-antibody reactions. Meanwhile, AuPd-NH_2-fMnO_2, the signal amplifier was employed as a carrier tag to label secondary antibody (Ab_2), which showed excellent catalytic ability toward H_2O_2. The AuPd NPs boosted TBBPA oxidation, thereby generating improved signals. Hence, under optimal conditions, the competitive biosensor presented superior performances, as good sensitivity (LOD, 0.10ng/mL; based on S/N = 3) and satisfactory accuracy (recoveries, 84-120 %; CV, 2.35-6.24 %), the proposed method was employed to analyze TBBPA in waters from various sources, indicating a great potential for the sensitive determination of trace TBBPA in aquatic environments.