Division of Physical Biology & Bioimaging Center, Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences , Shanghai, China 201800.
Anal Chem. 2014 Mar 4;86(5):2285-8. doi: 10.1021/ac500251t. Epub 2014 Feb 17.
Because of the short size and low abundance of microRNAs, it is challenging to develop fast, inexpensive, and simple biosensors to detect them. In this work, we have demonstrated a new generation (the third generation) of E-DNA sensor for the sensitive and specific detection of microRNAs. Our third generation of E-DNA sensor can sensitively detect microRNA target (microRNA-141) as low as 1 fM. The excellent specificity has been demonstrated by its differential ability to the highly similar microRNA analogues. In our design, the use of DNA tetrahedron ensures the stem-loop structure in well controlled density with improved reactivity. The regulation of the thermodynamic stability of the stem-loop structure decreases the background signal and increases the specificity as well. The enzymes attached bring the electrocatalytic signal to amplify the detection. The combination of these effects improves the sensitivity of the E-DNA sensor and makes it suitable to the microRNA detection. Finally, our third generation of E-DNA sensor is generalizable to the detection of other micro RNA targets (for example, microRNA-21).
由于 microRNAs 体积小、丰度低，因此开发快速、廉价且简单的生物传感器来检测它们具有一定挑战性。在这项工作中，我们展示了一种新型（第三代）E-DNA 传感器，用于灵敏和特异性地检测 microRNAs。我们的第三代 E-DNA 传感器可以灵敏地检测低至 1 fM 的 microRNA 靶标（microRNA-141）。其优异的特异性已通过其对高度相似的 microRNA 类似物的差异能力得到证明。在我们的设计中，使用 DNA 四面体确保了在受控密度下形成茎环结构，从而提高了反应性。调节茎环结构的热力学稳定性降低了背景信号并提高了特异性。附着的酶带来了电催化信号以放大检测。这些效果的结合提高了 E-DNA 传感器的灵敏度，使其适用于 microRNA 检测。最后，我们的第三代 E-DNA 传感器可推广用于检测其他 microRNA 靶标（例如，microRNA-21）。
