In this work, a novel sandwich-type aptasensor was designed for the ultrasensitive recognition of trace mercury ions in water. Numerous oriented platinum nanotube arrays (PtNAs) were in-situ crystallized on a flexible electrode as a sensing interface, while thionine labelled Fe₃O₄/rGO nanocomposites as signal amplifiers. Both PtNAs/CF and nanocomposites were synthesized by easy hydrothermal processes. With their large surface area, it was favorable for electrochemical performance and immobilization of capture DNAs (cDNA) and report DNAs (rDNA). Upon the existence of Hg²⁺, partial linker DNAs were tightly bound with cDNAs through thymine-Hg²⁺-thymine pairing (T-Hg²⁺-T). Then rDNAs attached Fe₃O₄/rGO nanoprobes were fixed on the electrode through the match of remaining linker DNAs and rDNAs. Under the optimal conditions, the Hg²⁺ aptasensor showed a synergistic amplification performance with a wide linear range from 0.1nM to 100 nM, as well as a low detection limit of 30 pM. Moreover, the as-prepared aptasensor also exhibited reliable performance for assay in real lake water samples.

在这项工作中，设计了一种新型的三明治型适体传感器，用于超灵敏地识别水中的痕量汞离子。许多取向的铂纳米管阵列（PtNAs）在柔性电极上原位结晶，作为传感界面，而硫氨酸标记的Fe ₃ O ₄ / rGO纳米复合材料作为信号放大器。PtNAs / CF和纳米复合材料都是通过简单的水热过程合成的。由于它们的表面积大，有利于电化学性能以及捕获DNA（cDNA）和报告DNA（rDNA）的固定化。存在Hg ^2+时，部分连接子DNA通过胸腺嘧啶-Hg 2 ^+-胸腺嘧啶配对（T-Hg ²⁺ -T）与cDNA紧密结合。然后rDNA连接到Fe ₃通过剩余的接头DNA和rDNA的匹配，将O ₄ / rGO纳米探针固定在电极上。在最佳条件下，Hg ²⁺适体传感器表现出协同放大性能，线性范围从0.1nM到100 nM，检测限低至30 pM。此外，所制备的适体传感器还显示出在真实湖水样品中进行分析的可靠性能。