Morphology-Controlled DPA Nano Blocks as Electrochemiluminescence Emitters for MicroRNA Detection with One Step DNA Walker Amplification.

作者：Liu Jia Li; Tang Zhi Ling; Zhang Jia Qi; Chai Yaqin; Zhuo Ying; Yuan Ruo

来源：ANALYTICAL CHEMISTRY, 2018.

DOI：10.1021/acs.analchem.8b00209

The electrochemiluminescence (ECL) properties of polycyclic aromatic hydrocarbons (PAHs) are excellent on account of the high photoluminescence quantum yield. However, the poor solubility and radical instability of PAHs in the aqueous solution severely restricted the further biological application. Here, 9,10 - diphenylanthracene (DPA) nano blocks (NBs) with good dispersibility and stability in aqueous solution were prepared according to morphology-controlled technology employing water-soluble polymers as a protectant. Furthermore, an ECL "off-on" switch biosensor was developed based on a novel ECL ternary system with DPA NBs as luminophore, dissolved O2 as co-reactant, and Pt-Ag alloy nanoflowers as the co-reaction accelerator, which achieved a high-intense initial ECL signal. Subsequently, the Fc-DNA as ECL signal quencher were assembled on the electrode surface to quench the initial ECL signal for a "signal-off" state. Meanwhile, DNA swing arm was modified on the electrode surface for one step DNA walker amplification. Interestingly, in the presence of miRNA-141 and T7 Exo, the one step DNA walker amplification was executed to recover a strong ECL signal as a "signal on" state by the digestion of Fc-DNA. Thus, the developed ECL "off-on" switch biosensor possesses a detection limit down to 29.5 aM for ultrasensitive detection of miRNA-141, which is expected to be applicable to the detection of miRNA in clinic tumor cells.