State Key Laboratory of Analytical Chemistry for Life Science and Collaborative Innovation Center of Chemistry for Life Sciences, School of Chemistry and Chemical Engineering , Nanjing University , Nanjing 210023 , China.
Anal Chem. 2018 Nov 20;90(22):13723-13728. doi: 10.1021/acs.analchem.8b04141. Epub 2018 Oct 31.
In this study, we proposed a dual-wavelength electrochemiluminescence resonance energy transfer (ECL-RET) ratiometric sensor combined with duplex-specific nuclease (DSN)-assisted target recycling amplification to detect microRNAs (miRNAs). Due to the perfect overlapping of spectra, the gold-nanoparticle-luminol-layered-double-hydroxides (Au NP-luminol-LDH) nanocomposite and gold nanoclusters (Au NCs) exhibited excellent ECL-RET effect with high efficiency. The Au NP-luminol-LDH donor exhibits a strong and stable ECL emission at the wavelength peak of 440 nm, while the Au NC acceptor has an emission peak at 620 nm. Upon the introduction of DSN and target miRNAs, the specific DNA-RNA binding and nuclease cleaving could trigger the detachment of capture Au NCs-DNA from the surface of Au NP-luminol-LDH, resulting in an increased ECL signal of Au NP-luminol-LDH and a decreased fluorescence signal of Au NCs. By measuring the ratio of optical signals at 440 and 620 nm, the designed sensor provided a quantitative readout proportional to the target miRNAs concentration in the range of 10 aM to 100 pM with a lower detection limit (LOD) of 9.4 aM.
在本研究中，我们提出了一种双波长电化学发光共振能量转移（ECL-RET）比率传感器，结合双链特异性核酸酶（DSN）辅助的靶标循环扩增来检测 microRNAs（miRNAs）。由于光谱的完美重叠，金纳米粒子-鲁米诺层状双氢氧化物（Au NP-luminol-LDH）纳米复合材料和金纳米簇（Au NCs）表现出高效的优异 ECL-RET 效应。Au NP-luminol-LDH 供体在 440nm 的波长峰处表现出强而稳定的 ECL 发射，而 Au NC 受体在 620nm 处具有发射峰。引入 DSN 和靶标 miRNAs 后，特异性 DNA-RNA 结合和核酸酶切割会触发捕获 Au NCs-DNA 从 Au NP-luminol-LDH 表面脱离，从而导致 Au NP-luminol-LDH 的 ECL 信号增加和 Au NCs 的荧光信号减少。通过测量 440nm 和 620nm 处的光学信号比值，设计的传感器提供了与靶标 miRNAs 浓度成正比的定量读数，在 10 aM 至 100 pM 的范围内具有较低的检测限（LOD）为 9.4 aM。
