Key Laboratory of Luminescence and Real-Time Analytical Chemistry (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing, 400715, PR China.
Key Laboratory of Luminescence and Real-Time Analytical Chemistry (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing, 400715, PR China.
Biosens Bioelectron. 2020 Feb 15;150:111872. doi: 10.1016/j.bios.2019.111872. Epub 2019 Nov 10.
A strong hydroxide (OH)-dependent ECL emission of carboxyl functionalized-poly (9,9-di-n-octylfluorenyl-2,7-diyl) polymer dots (PFO Pdots) was observed at +1.25 V, which is significantly stronger than the emission at +1.95 V reported in previous work. Moreover, hydrogen peroxide (HO) can efficiently quench OH-dependent ECL emission of PFO Pdots. Based on this discovery, a signal "off-on" ECL biosensing platform for microRNA-155 (miRNA-155) was developed. Firstly, PFO Pdots were modified onto the electrode to capture DNA duplex track-locker. In the presence of HO in the test solution, the ECL signal of PFO Pdots was quenched to obtain a signal-off state. Subsequently, the DNA walker produced through the target miRNA-155-triggered catalytic hairpin assembly (CHA) walked along the DNA duplex track-locker to output amounts of G-rich short chain, forming a hemin/G-quadruplex. With the consumption of HO by hemin/G-quadruplex, the ECL signal would be restored to a signal-on state, thus achieving an ultrasensitive detection of miRNA-155. The detection limit was low as 12.2 aM. Furthermore, our proposed biosensor demonstrated a tremendous selectivity and admirable stability, and exhibited a satisfactory performance for determinating intracellular miRNA-155. The integration of excellent ECL performance of PFO Pdots without any exogenous species or dissolved O as co-reactant and a highly efficient quenching effect of HO on such an ECL emission will provide an attractive ECL platform for bioanalysis and clinical diagnosis.
在 +1.25 V 处观察到羧酸功能化聚（9,9-二正辛基芴-2,7-二基）聚合物点（PFO Pdots）的强氢氧化物（OH）依赖的电致化学发光（ECL）发射，这比以前工作中报道的 +1.95 V 处的发射要强得多。此外，过氧化氢（HO）可以有效地猝灭 PFO Pdots 的 OH 依赖的 ECL 发射。基于这一发现，开发了用于 microRNA-155（miRNA-155）的信号“关-开”ECL 生物传感平台。首先，将 PFO Pdots 修饰到电极上以捕获 DNA 双链轨道锁。在测试溶液中存在 HO 的情况下，PFO Pdots 的 ECL 信号被猝灭以获得信号关闭状态。随后，通过目标 miRNA-155 触发的催化发夹组装（CHA）产生的 DNA 行走器沿着 DNA 双链轨道锁行走，输出大量富含 G 的短链，形成血红素/G-四链体。随着血红素/G-四链体消耗 HO，ECL 信号将恢复到信号开启状态，从而实现对 miRNA-155 的超灵敏检测。检测限低至 12.2 aM。此外，我们提出的生物传感器表现出巨大的选择性和令人钦佩的稳定性，并在测定细胞内 miRNA-155 方面表现出令人满意的性能。PFO Pdots 的出色 ECL 性能的集成，无需任何外源性物质或溶解氧作为共反应物，以及 HO 对这种 ECL 发射的高效猝灭作用，将为生物分析和临床诊断提供有吸引力的 ECL 平台。
