Henan Joint International Research Laboratory of Environmental Pollution Control Materials, College of Chemistry and Chemical Engineering, Henan University, Kaifeng, Henan Province, 475004, PR China.
Henan Joint International Research Laboratory of Environmental Pollution Control Materials, College of Chemistry and Chemical Engineering, Henan University, Kaifeng, Henan Province, 475004, PR China.
Biosens Bioelectron. 2019 Oct 1;142:111525. doi: 10.1016/j.bios.2019.111525. Epub 2019 Jul 23.
In this work, a metallic composite with strong electrocatalytic property was designed by uniformly decorating Pt and Sn nanoparticles on the surface of TiO nanorods (Pt-Sn@TiO). A detection scheme was then developed based on a dual signal amplification strategy involving the Pt-Sn@TiO composite and exonuclease assisted target recycling. The Pt-Sn@TiO composite exhibited an enhanced oxygen reduction current owing to the synergistic effect between Pt and Sn, as well as high exposure of Pt (111) crystal face. Initially, a Pt-Sn@TiO modified glassy carbon electrode produced an amplified electrochemical signal for the reduction of dissolved oxygen in the analyte solution. Next, a DNA with a complementary sequence to a streptomycin aptamer (cDNA) was immobilised on the Pt-Sn@TiO modified electrode, followed by the streptomycin aptamer that hybridised with cDNA. The corresponding oxygen reduction current was diminished by 51% attributable to the hindrance from the biomolecules. After a mixture of streptomycin and RecJ exonuclease was introduced, both the streptomycin-aptamer complex and the cDNA were cleaved from the electrode, making the Pt-Sn and Pt (111) surface available for oxygen reduction. RecJ would also release streptomycin from the streptomycin-aptamer complex, allowing it to complex again with aptamers on the electrode. This has then promoted a cyclic amplification of the oxygen reduction current by 85%, which is quantitatively related to streptomycin. Under optimal conditions, the aptasensor exhibited a linear range of 0.05-1500 nM and a limit of detection of 0.02±0.0045 nM streptomycin. The sensor was then used in the real-life sample detection of streptomycin to demonstrate its potential applications to bioanalysis.
在这项工作中，通过在 TiO 纳米棒（Pt-Sn@TiO）表面均匀修饰 Pt 和 Sn 纳米颗粒，设计了一种具有强电催化性能的金属复合材料。然后，基于涉及 Pt-Sn@TiO 复合材料和外切酶辅助目标循环的双重信号放大策略，开发了一种检测方案。Pt-Sn@TiO 复合材料由于 Pt 和 Sn 的协同作用以及 Pt(111)晶面的高暴露，表现出增强的氧还原电流。最初，在 Pt-Sn@TiO 修饰的玻碳电极上产生了一个放大的电化学信号，用于还原分析物溶液中的溶解氧。接下来，将与链霉素适体（cDNA）互补的序列的 DNA 固定在 Pt-Sn@TiO 修饰的电极上，然后是与 cDNA 杂交的链霉素适体。由于生物分子的阻碍，相应的氧还原电流减少了 51%。在引入链霉素和 RecJ 外切酶的混合物后，电极上的链霉素-适体复合物和 cDNA 都被切割下来，使 Pt-Sn 和 Pt(111)表面可用于氧还原。RecJ 还会将链霉素从链霉素-适体复合物中释放出来，使其能够再次与电极上的适体结合。这通过 85%的氧还原电流的循环放大，与链霉素呈定量关系。在最佳条件下，该适体传感器的线性范围为 0.05-1500 nM，检测限为 0.02±0.0045 nM 链霉素。然后，该传感器用于链霉素的实际样品检测，以证明其在生物分析中的潜在应用。
