OFF/ON Red-Emitting Fluorescent Probes for Casein Recognition and Quantification Based on Indolium Derivatives

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• 作者：Wei Yang ; Chunlin Liu ; Qingyun Gao ; Jinya Du ; Ping Shen…
• 关键词：Fluorescent probes ; Red ; emitting ; Discrimination ; Hydrophobic protein ; Casein ; Quantification
• 刊名：Journal of Fluorescence
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：27
• 期：1
• 页码：391-398
• 全文大小：
• 刊物类别：Biomedical and Life Sciences
• 刊物主题：Biomedicine, general; Biological and Medical Physics, Biophysics; Biotechnology; Biochemistry, general; Analytical Chemistry;
• 出版者：Springer US
• ISSN：1573-4994
• 卷排序：27

文摘

Five derivatives of 2, 3, 3-trimethyl-3H-indolium containing different electron donor groups (H1 - H5) were synthesized for the determination of proteins. H3, a sensitive red-emitting fluorescent probe, was found for the discrimination of hydrophobic proteins from hydrophilic. The OFF - ON fluorescence switch of H3 was caused by the formation of twisted intramolecular charge-transfer (TICT) state when it combined with hydrophobic proteins in aqueous buffer. There was a good linear relationship between the emission intensity of H3 and the casein concentration (r = 0.9989). Based on this, a novel casein quantitative assay method was developed, and the method was applied to determinate casein in milk powder samples. Successfully, the results were in good agreement with Biuret method. In addition, a simple and sensitive method was established to differentiate and quantify three casein components (α-, β-, and κ-casein) due to their much different binding constants to H3 probe.