A novel quantum dots-based OFF-ON fluorescent biosensor for highly selective and sensitive detection of double-strand DNA

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• 作者：Zhengqing LiuAuthor Vitae ; Shaopu LiuAuthor Vitae ; Xiaodan WangAuthor Vitae ; Pingping LiAuthor Vitae ; Youqiu He ; ^{heyq@swu.edu.cn}Author Vitae
• 关键词：Quantum dots ; Double-strand DNA ; Photoinduced electron transfer ; Praseodymium(III)&ndash ; rutin complex
• 刊名：Sensors and Actuators B: Chemical
• 出版年：2013
• 出版时间：January, 2013
• 年：2013
• 卷：176
• 期：Complete
• 页码：1147-1153
• 全文大小：726 K

文摘

We have developed a novel biosensor for the rapid determination of double-strand (ds) DNA based on the photoinduced electron transfer (PET) from glutathione (GSH) capped CdTe quantum dots (QDs) to praseodymium(III)-rutin (Pr³⁺-rutin) complex. The biosensor was based on a fluorescence ¡°OFF-ON¡± mode. To provide the platform for dsDNA detection, the Pr³⁺-rutin complex was first employed as an effective fluorescence quencher to QDs through PET. Because of its strong binding af?nity with Pr³⁺-rutin complex, dsDNA can break up the low fluoresced ionic ensemble, set free the luminescent QDs. Thus, the recognition of dsDNA by Pr³⁺-rutin complex can be realized through the restoration of QDs fluorescence. The relative recovered fluorescence intensity is directly proportional to the concentration of herring sperm (hs) DNA between 0.0874 ¦Ìg mL^?1 and 20 ¦Ìg mL^?1, and the detection limit (3¦Ä/K) is 0.0262 ¦Ìg mL^?1. The entire experimental process does not require any chemical modification and coupling of CdTe QDs and dsDNA, greatly simplifying the experimental process. Some possible reaction mechanisms are discussed.