Chen Jinyang, Ji Xinghu, Tinnefeld Philip, He Zhike
Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, Wuhan University , Wuhan 430072, People's Republic of China.
NanoBioSciences Group, Institute for Physical and Theoretical Chemistry and Braunschweig Integrated Centre of Systems Biology (BRICS), and Laboratory for Emerging Nanometrology (LENA), Braunschweig University of Technology , Braunschweig, 38106, Germany.
ACS Appl Mater Interfaces. 2016 Jan 27;8(3):1786-94. doi: 10.1021/acsami.5b09678. Epub 2016 Jan 12.
In this work, a multifunctional template for selective formation of fluorescent silver nanoclusters (AgNCs) or copper nanoparticles (CuNPs) is put forward. This dumbbell-shaped (DS) DNA template is made up of two cytosine hairpin loops and an adenine-thymine-rich double-helical stem which is closed by the loops. The cytosine loops act as specific regions for the growth of AgNCs, and the double-helical stem serves as template for the CuNPs formation. By carefully investigating the sequence and length of DS DNA, we present the optimal design of the template. Benefiting from the smart design and facile synthesis, a simple, label-free, and ultrasensitive fluorescence strategy for adenosine triphosphate (ATP) detection is proposed. Through the systematic comparison, it is found that the strategy based on CuNPs formation is more sensitive for ATP assay than that based on AgNCs synthesis, and the detection limitation was found to be 81 pM. What's more, the CuNPs formation-based method is successfully applied in the detection of ATP in human serum as well as the determination of cellular ATP. In addition to small target molecule, the sensing strategy was also extended to the detection of biomacromolecule (DNA), which illustrates the generality of this biosensor.
在这项工作中，提出了一种用于选择性形成荧光银纳米簇（AgNCs）或铜纳米颗粒（CuNPs）的多功能模板。这种哑铃状（DS）DNA模板由两个胞嘧啶发夹环和一个由这些环封闭的富含腺嘌呤 - 胸腺嘧啶的双螺旋茎组成。胞嘧啶环充当AgNCs生长的特定区域，而双螺旋茎作为CuNPs形成的模板。通过仔细研究DS DNA的序列和长度，我们展示了模板的优化设计。得益于这种巧妙的设计和简便的合成方法，提出了一种用于三磷酸腺苷（ATP）检测的简单、无标记且超灵敏的荧光策略。通过系统比较发现，基于CuNPs形成的策略对ATP检测比基于AgNCs合成的策略更灵敏，检测限为81 pM。此外，基于CuNPs形成的方法成功应用于人体血清中ATP的检测以及细胞ATP的测定。除了小分子靶标分子外，该传感策略还扩展到生物大分子（DNA）的检测，这说明了这种生物传感器的通用性。
