A 3D CdTe QDs-DNA Nano-Reticulation as Highly Efficient Electrochemiluminescent Emitter for ultrasensitive Detection of MicroRNA from Cancer Cells

In this work, a novel three-dimensional cadmium telluride quantum dots–DNA nanoreticulation (3D CdTe QDs–DNA-NR) was used as a signal probe with the dual-legged DNA walker circular amplification as target conversion strategy to establish a pioneering electrochemiluminescence (ECL) biosensing strategy for ultrasensitive detection of microRNA-21 form cancer cells. Herein, such a 3D luminous nanomaterial with reticular structure not only supported abundant CdTe QDs to avoid the inner filter effect for obtaining a high ECL efficiency but also contained the hemin/G-quadruplex as coreaction accelerator in the 3D CdTe QDs–DNA-NR/S2O82– system for the enhancement of ECL intensity. Furthermore, with the target-induced dual-legged DNA walker circular amplification strategy, a mass of output DNA was produced to connect with the 3D CdTe QDs–DNA-NR for the construction of the ECL biosensor, which realized the ultrasensitive detection of microRNA-21 from 100 aM to 100 pM and the detection limit down to 34 aM. Significa...