State Key Laboratory Base of Novel Functional Materials and Preparation Science, Faculty of Materials Science and Chemical Engineering, Ningbo University, Ningbo 315211, PR China.
State Key Laboratory Base of Novel Functional Materials and Preparation Science, Faculty of Materials Science and Chemical Engineering, Ningbo University, Ningbo 315211, PR China.
Talanta. 2018 Mar 1;179:28-36. doi: 10.1016/j.talanta.2017.10.016. Epub 2017 Oct 12.
An ultrasensitive electrochemical aptasensor for multiplex antibiotics detection based on endonuclease and exonuclease assisted dual recycling amplification strategy was proposed. Kanamycin and chloramphenicol were selected as candidates. Firstly, aptamers of the antibiotics were immobilized on bar A and then binding with their endonuclease labeled complementary DNA strands to construct enzyme-cleavage probes. Secondly, The nano zirconium-metal organic framework (NMOF) particles with 1,4-benzene-dicarboxylate (BDC) as linker was defined as UiO-66. And its updated version, hierarchically porous UiO-66 (HP-UIO-66) decorated with different electroactive materials as signal tags were synthesized. Then they were immobilized on bar B linked by two duplex DNA strands which can be specifically cleaved by corresponding enzyme-cleavage probes in bar A. Once targets were introduced into system, aptamers can capture them and then release enzyme-cleavage probes. In the presence of exonuclease-I, exonuclease assisted target recycling amplification was triggered and more enzyme-cleavage probes were released into solution. The probes can trigger endonuclease assisted recycles and repeatedly cleave their corresponding duplex DNA strands on bar B then released numerous signal tags into supernatant. Thus two recycling amplification was performed in the system. Finally, MB and Fc in the signal tags were detected by square wave voltammetry after removing bar A/B and the current intensities were correspondent with the concentration of KANA and CAP respectively. Under the optimum condition, the limits of detection for the KANA and CAP were 35fM and 21fM respectively with a wide linear range from 1 × 10 to 50nM. This dual recycling amplification detection system exhibited high sensitivities and specificity. It can be easily extended to detect other targets if changing the corresponding aptamers and has potential application values for screening of multiplex antibiotics residues in food safety.
基于内切酶和exonuclease 辅助双重循环放大策略，提出了一种超灵敏的电化学适体传感器，用于多重抗生素检测。选择卡那霉素和氯霉素作为候选物。首先，抗生素的适体被固定在棒 A 上，然后与它们的内切酶标记互补 DNA 链结合，构建酶切割探针。其次，纳米氧化锆-金属有机骨架（NMOF）颗粒以 1,4-苯二甲酸（BDC）为连接体，定义为 UiO-66。其更新版本，具有不同电活性材料作为信号标记的分层多孔 UiO-66（HP-UIO-66）被合成。然后，它们被固定在棒 B 上，棒 B 通过两条双链 DNA 连接，双链 DNA 可以被棒 A 中的相应酶切割探针特异性切割。一旦引入靶标，适体可以捕获它们，然后释放酶切割探针。在exonuclease-I 的存在下，触发 exonuclease 辅助的靶标循环扩增，更多的酶切割探针被释放到溶液中。探针可以触发内切酶辅助的循环，并反复切割棒 B 上的相应双链 DNA 链，然后将大量信号标记物释放到上清液中。因此，系统中进行了两次循环放大。最后，在去除棒 A/B 后，通过方波伏安法检测信号标签中的 MB 和 Fc，电流强度与 KANA 和 CAP 的浓度相对应。在最佳条件下，KANA 和 CAP 的检测限分别为 35fM 和 21fM，线性范围从 1×10到 50nM 很宽。这种双重循环放大检测系统具有很高的灵敏度和特异性。如果改变相应的适体，它可以很容易地扩展到检测其他靶标，并且在食品安全中筛选多重抗生素残留方面具有潜在的应用价值。
