A competitive electrochemical immunosensor based on bimetallic nanoparticle decorated nanoflower-like MnO2 for enhanced peroxidase-like activity and sensitive detection of Tetrabromobisphenol A

Abstract

In this work, a novel competitive electrochemical immunosensor was developed based on gold palladium bimetallic nanoparticles which were successfully synthesized and modified by amine (-NH2) functionalized-nanoflower-like manganese oxide (NH2-fMnO2) 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-NH2-fMnO2, the signal amplifier was employed as a carrier tag to label secondary antibody (Ab2), which showed excellent catalytic ability toward H2O2. The AuPd NPs boosted TBBPA oxidation, thereby generating improved signals. Hence, under optimal conditions, the competitive biosensor presented superior performances, as good sensitivity (LOD, 0.10 ng/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.