Bipotential-resolved electrochemiluminescence biosensor based on Bi2S3@Au nanoflowers for simultaneous detection of Cd(II) and ampicillin in aquatic products

In this paper, an electrochemiluminescence (ECL) biosensor was constructed using Bi2S3@Au nanoflowers as the based nanomaterial and Au@luminol and CdS QDs as independent ECL emission signal respectively. As the substrate of the working electrode, Bi2S3@Au nanoflowers improved the effective area of electrode and accelerated electron transfer rate between gold nanoparticles and aptamer, provided a good interface environment for the loading of luminescent materials. Then, the Au@luminol functionalized DNA2 probe was used as an independent ECL signal source under positive potential and recognized Cd(II), while the CdS QDs functionalized DNA3 probe was used as an independent ECL signal source under negative potential and recognized ampicillin. The simultaneous detection of Cd(II) and ampicillin in different concentrations are realized. This sensor not only has good selectivity and high sensitivity in real sample detection, but also open up a novel way to construct multi-target ECL biosensor for simultaneous detection.