General Surgery Department, Shanxi Bethune Hospital, Shanxi Academy of Medical Sciences, Tongji Shanxi Hospital, Third Hospital of Shanxi Medical University, Taiyuan 030032, China.
Department of Chemistry, Zhejiang Sci-Tech University, Hangzhou 310018, China.
Molecules. 2023 Jul 3;28(13):5186. doi: 10.3390/molecules28135186.
A rapid and convenient homogeneous aptamer sensor with high sensitivity is highly desirable for the electrochemical detection of tumor biomarkers. In this work, a homogeneous electrochemical aptamer sensor is demonstrated based on a two-dimensional (2D) nanocomposite probe and nanochannel modified electrode, which can realize sensitive detection of carcinoembryonic antigen (CEA). Using π-π stacking and electrostatic interaction, CEA aptamer (Apt) and cationic redox probe (hexaammineruthenium(III), Ru(NH)) are co-loaded on graphite oxide (GO), leading to a 2D nanocomposite probe (Ru(NH)/Apt@GO). Vertically ordered mesoporous silica-nanochannel film (VMSF) is easily grown on the supporting indium tin oxide (ITO) electrode (VMSF/ITO) using the electrochemical assisted self-assembly (EASA) method within 10 s. The ultrasmall nanochannels of VMSF exhibits electrostatic enrichment towards Ru(NH) and size exclusion towards 2D material. When CEA is added in the Ru(NH)/Apt@GO solution, DNA aptamer recognizes and binds to CEA and Ru(NH) releases to the solution, which can be enriched and detected by VMSF/ITO electrodes. Based on this mechanism, CEA can be an electrochemical detection ranging from 60 fg/mL to 100 ng/mL with a limit of detection (LOD) of 14 fg/mL. Detection of CEA in human serum is also realized. The constructed homogeneous detection system does not require the fixation of a recognitive aptamer on the electrode surface or magnetic separation before detection, demonstrating potential applications in rapid, convenient and sensitive electrochemical sensing of tumor biomarkers.
一种快速、便捷的均相适体传感器，具有高灵敏度，对于电化学检测肿瘤标志物非常理想。本工作基于二维（2D）纳米复合材料探针和纳米通道修饰电极，展示了一种均相电化学适体传感器，可实现对癌胚抗原（CEA）的灵敏检测。通过π-π堆积和静电相互作用，CEA 适体（Apt）和阳离子氧化还原探针（六氨合钌（III），Ru(NH))共负载在氧化石墨（GO）上，得到 2D 纳米复合材料探针（Ru(NH)/Apt@GO）。垂直有序介孔硅-纳米通道膜（VMSF）可通过电化学辅助自组装（EASA）方法在 10 秒内轻松地在支持的铟锡氧化物（ITO）电极（VMSF/ITO）上生长。VMSF 的超小孔纳米通道对 Ru(NH)表现出静电富集作用，对 2D 材料表现出尺寸排除作用。当 CEA 被添加到 Ru(NH)/Apt@GO 溶液中时，DNA 适体识别并与 CEA 结合，Ru(NH)释放到溶液中，可通过 VMSF/ITO 电极进行富集和检测。基于这种机制，CEA 的电化学检测范围从 60 fg/mL 到 100 ng/mL，检测限（LOD）为 14 fg/mL。还实现了对人血清中 CEA 的检测。所构建的均相检测系统不需要在检测前将识别适体固定在电极表面或进行磁分离，在肿瘤标志物的快速、便捷和灵敏电化学传感方面具有潜在应用。
