Magnetic Ni/Fe layered double hydroxide nanosheets as enhancer for DNA hairpin sensitive detection of miRNA

Publication date: 1 September 2018
Source:Talanta, Volume 187
Author(s): Jun Sun, Yana Li, Chengbo Chen, Tong Qi, Dasha Xia, Wei Mao, Tongyi Yang, Lizhuang Chen, Wei Shen, Sheng Tang
A new non-enzyme method based on hybridization chain reaction (HCR) and colorimetric reaction catalyzed by magnetic Ni/Fe layered double hydroxide (LDH) nanosheets was developed for detection of microRNA (miRNA), let-7b. The DNA hairpins from HCR were separated and adsorbed by Ni/Fe LDH. The peroxidase-like activity of Ni/Fe LDH was found to be enhanced by the DNA hairpins on the surface. The factors, such as ratio of Ni/Fe and concentration of DNA hairpins, related to the catalytic activity were evaluated and the mechanism was discussed. The results of this new detection method for let-7b provided low limit of detection (0.36 fM), wide linear range (0.01 pM to 200 pM) with good linearity (r² = 0.9968). The optimized method was applied to analyze let-7b in real samples, lung cancer cells. This work demonstrated a new and cost-effective approach for efficient detection of miRNA.

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