Determination of 2-methoxyestradiol by chemiluminescence based on luminol–KMnO4–CdTe quantum dots system

•GSH capped CdTe QDs was synthesized to enhance the CL of luminol–KMnO4 system.•A new CL system of 2-ME-CdTe QDs–luminol–KMnO4 was developed.•Highly sensitive and selective for determination of 2-ME in plasma samples.•The possible enhancement mechanism of CdTe QDs on luminol–KMnO4 CL was investigated.

In this study, water-soluble CdTe quantum-dots (QDs) capped with glutathione (GSH) was synthesized. It was found that CdTe QDs could greatly enhance the chemiluminescence (CL) emission from the luminol–KMnO4 system in alkaline medium, and 4 nm CdTe QDs was used as catalysts to enhance the reaction sensitivity. The CL intensity of CdTe QDs–luminol–KMnO4 was strongly inhibited in the presence of 2-methoxyestradiol (2-ME) and the relative CL intensity was in linear correlation with the concentration of 2-ME. Based on this inhibition, a novel CL method with a lower detection limit and wider linear range was developed for the determination of 2-ME. The detection limit of plasma samples was 3.07 × 10−10 g mL−1 with a relative standard deviation of 0.24% for 8.0 × 10−9 g mL−1 2-ME. The method was successfully applied for determination of 2-ME in plasma samples. The possible CL reaction mechanism was also discussed briefly.

Graphical abstractThe intensity of emitted light from CdTe quantum dots–luminal–KMnO4 is described as a novel chemiluminescence (CL) reaction for determination of 2-ME. The addition of CdTe QDs into luminol–KMnO4 system could induce a great increase in CL signals, and the CL intensity declined in the presence of 2-ME.Figure optionsDownload full-size imageDownload as PowerPoint slide