▎ 摘　　要

We report on a widely applicable approach for protein detection by using triple-helix DNA mediated CuInS2 quantum dot (QD) and graphene oxide (GO) nanocomposite. The CuInS2 QDs were coated with mercaptopropionic acid and then covalently linked to a hairpin aptamer against lysozyme (HLA). Single-stranded DNA (triple helix-forming oligonucleotide; THFO) readily absorbs on the surface of GO via pi-stacking interaction, and this results in the formation of THFO-GO. If HLA-CuInS2 QDs are added to the THFO-GO system, the fluorescence of HLA-CuInS2 QDs (at excitation/emission wavelengths of 590/665 nm) is quenched. Lysozyme has a higher affinity for HLA than THFO. Therefore, in the presence of lysozyme, it will bind to the HLA-CuInS2 QD and displace the THFO-GO. This results in the restoration of fluorescence that is related to the concentration of lysozyme. The fluorescence of the QDs is turned on. The calibration plot is linear in the 0.01 to 1.8 ng center dot mLaEuro3/4(1) concentration range, with a 3 pg center dot mLaEuro3/4(1) detection limit (at a signal-to-noise ratio of 3). The method was also applied to study the inhibition of lysozyme by Ivy (Ec) . In our perception, this method has a wide scope in that it may become applicable to any protein for which an appropriate aptamer is available.