A Promising CdSe@CdS-Quantum Dots-Cysteine for the Determination of Trace IgE by Solid Substrate Room Temperature Phosphorescence Immunoassay

作者：Liu Jia Ming^*; Lin Li ping; Liu Zhen Bo; Yang Min Lan; Wang Xin xing; Zhang Li hong; Cui Ma lin; Jiao Li

来源：Journal of Fluorescence, 2012, 22(1): 419-429.

DOI：10.1007/s10895-011-0975-3

• CdSe@CdS-quantum dots-cysteine
• Phosphorescent quantum dot probe
• Immunoglobulin E
• Solid substrate room temperature phosphorescence immunoassay
• Diagnosis and prediction of human diseases

The labelling reagent CdSe@CdS-QDs-Cys (QDs-Cys) with the grain diameter of 4.5 nm was synthesized by modifying CdSe@CdS quantum dots (QDs) with cysteine (Cys). At the same time, QDs-Cys-Ab(IgE), a phosphorescent quantum dot probe, was developed based on the labelling reaction between -COOH of QDs-Cys and -NH2 of goat anti human IgE antibody (Ab(IgE)). This probe with excellent biocompatibility and high specificity could not only emit strong and stable room temperature phosphorescence (RTP), but also could carry out specific immunoassay (IA) with immunoglobulin E (IgE), causing the RTP of the system to sharply enhance. Thus, a new solid substrate room temperature phosphorescence immunoassay (SSRTPIA) for the determination of IgE was established. The limit of quantification (LOQ) of the method was 0.12 fg spot(-1), corresponding concentration was 3.0x10(-13) g mL(-1) and sampling quantity was 0.40 mu L spot(-1). This highly selective, sensitive and accurate SSRTPIA has been applied to determine IgE in biological samples and diagnose diseases, and the results agreed well with those obtained by enzyme-link immunoassay (ELISA). Meanwhile, the mechanisms of QDs-Cys labelling Ab(IgE) and the determination of IgE by SSRTPIA were also discussed.

• 出版日期2012-1
• 单位闽南师范大学