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MicroRNA-mediated signal amplification coupled with GNP/dendrimers on a mass-sensitive biosensor and its applications in intracellular microRNA quantification

Guo, Yingshu, Wang, Yujie, Yang, Guangxu, Xu, Jing-Juan, Chen, Hong-Yuan
Biosensors & bioelectronics 2016 v.85 pp. 897-902
DNA, biosensors, gold, microRNA, nanogold, neoplasms, quantitative polymerase chain reaction, recycling, reverse transcriptase polymerase chain reaction
Here, a mass-sensitive microRNA sensing surface is developed by utilizing a probe DNA/gold nanoparticles (GNP)/dendrimer composite coupling with an enzymatic amplification process. The probe DNA/GNP/dendrimer composite is prepared via the covalent coupling between the NH2 groups in PAMAM or DNA and the COOH group on GNP. Target microRNA binds to a stem-loop-structured DNA on maganatic NPs, forming a heteroduplex. By enzyme recycling amplification, a large number of linker sequences are produced on MNPs. Via the combination of probe DNA, the linker DNA on MNPs and a capture DNA on gold chip, the DNA/GNP/dendrimer probe could be assembled on the surface of gold chip inducing a sensitive frequency response. It presents an excellent performance in microRNA-203 quantification with a detection linear range of 1.0×10⁻¹¹–1.0×10⁻⁹M. Both the success in discriminating expressing miroRNA-203 in MCF-7 cell and the well agreement with the commercial qRT-PCR detection method implied its potential application in early cancer diagnosis for future.