Key Laboratory of Luminescent and Real-Time Analytical Chemistry (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, China.
Key Laboratory of Luminescent and Real-Time Analytical Chemistry (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, China.
Biosens Bioelectron. 2016 Sep 15;83:287-92. doi: 10.1016/j.bios.2016.04.060. Epub 2016 Apr 22.
In this work, a sensitive electrochemical aptasensor was designed for lipopolysaccharide (LPS) detection based on Ce-based metal-organic frameworks (Ce-MOFs) and Zn(2+) dependent DNAzyme-assisted recycling as dual signal amplifiers. Herein, Ce-MOFs were decorated with gold nanoparticles (AuNPs) to obtain AuNPs/Ce-MOFs, and the resultant AuNPs/Ce-MOFs not only acted as nanocarriers to capture -SH terminated hairpin probes 2 (HP2) for acquiring HP2/AuNPs/Ce-MOFs signal probes, but also as catalysts to catalyze the oxidation of ascorbic acid (AA). In the presence of target LPS, report DNA was released from the prepared duplex DNA and then hybridized with hairpin probes 1 (HP1, which were immobilized on the electrode). With the help of Zn(2+), report DNA could act as Zn(2+) dependent DNAzyme to cleave HP1 circularly. Then a large amount of capture probes were produced on the electrode to combine with HP2/AuNPs/Ce-MOFs signal probes. When the detection solution contained electrochemical substrate of AA, AuNPs/Ce-MOFs could oxide AA to obtain enhanced signal. Under the optimized conditions, this proposed aptasensor for LPS exhibited a low detection limit of 3.3 fg/mL with a wide linear range from 10fg/mL to 100ng/mL.
在这项工作中，设计了一种基于 Ce 基金属有机框架（Ce-MOFs）和 Zn(2+) 依赖的 DNA 酶辅助循环作为双重信号放大器的敏感电化学适体传感器，用于检测脂多糖（LPS）。在此，Ce-MOFs 被修饰上金纳米粒子（AuNPs），得到 AuNPs/Ce-MOFs，所得到的 AuNPs/Ce-MOFs 不仅作为纳米载体来捕获 -SH 终止的发夹探针 2（HP2），以获取 HP2/AuNPs/Ce-MOFs 信号探针，而且还作为催化剂来催化抗坏血酸（AA）的氧化。在存在靶标 LPS 的情况下，报告 DNA 从制备的双链 DNA 中释放出来，然后与发夹探针 1（HP1，固定在电极上）杂交。在 Zn(2+) 的帮助下，报告 DNA 可以作为 Zn(2+) 依赖的 DNA 酶来循环切割 HP1。然后，大量的捕获探针在电极上产生，与 HP2/AuNPs/Ce-MOFs 信号探针结合。当检测溶液中含有 AA 的电化学底物时，AuNPs/Ce-MOFs 可以将 AA 氧化，以获得增强的信号。在优化条件下，该 LPS 适体传感器的检测限低至 3.3 fg/mL，线性范围从 10 fg/mL 到 100ng/mL 很宽。
