Ministry of Education Key Laboratory of Synthetic and Natural Functional Molecular Chemistry, Shaanxi Provincial Key Laboratory of Electroanalytical Chemistry, College of Chemistry & Materials Science, Northwest University, Xi'an, Shaanxi, 710127, China; Department of Applied Chemistry, Yuncheng University, Yuncheng, Shanxi, 044000, China.
Ministry of Education Key Laboratory of Synthetic and Natural Functional Molecular Chemistry, Shaanxi Provincial Key Laboratory of Electroanalytical Chemistry, College of Chemistry & Materials Science, Northwest University, Xi'an, Shaanxi, 710127, China.
Biosens Bioelectron. 2022 Apr 1;201:113963. doi: 10.1016/j.bios.2022.113963. Epub 2022 Jan 5.
Controllable transport of ions, molecules or fluids in bioinspired nanochannels is crucial to study biointeraction occurred in confined space and also develop biosensing platforms or devices. Herein, ferrofluids transport in biofunctionalized nanochannels was investigated and a novel electrochemical biosensing platform with the characteristic of label-free, high sensitivity and rapid response was constructed. The hydrophilic ferrofluids can flux swiftly through the antibody-immobilized nanochannels with the assistance of a permanent magnet. It was initially found that the presence of ferrofluids would depress the redox current of the electrochemical probe [Fe(CN)]. The mechanism of the depressing effect was ascribed to the constrained diffusion of [Fe(CN)] which lowered the concentration of it at the electrode surface and the weak adsorption of the ferrofluids which increased the charge transfer resistance of the interface. Therefore, redox current of the probe was applied to indicate the amount of the ferrofluids fluxing through the bioinspired nanochannels. The steric hindrance of the bioinspired nanochannels changed with the amount of the corresponding target being incubated, resulting in quantitative variation of the redox current. In this way, electrochemical biosensing platform based on ferrofluids transport was constructed. Using carbohydrate antigen 153 (CA153) as a model target, a low detection limit of 0.0013 U·mL was acquired. This magnetic-controlled bioelectrochemical platform was expected to be expanded to other applications such as genetic testing, drug analysis, and molecular identification.
在仿生纳米通道中对离子、分子或流体进行可控传输对于研究受限空间中发生的生物相互作用以及开发生物传感平台或器件至关重要。本文研究了生物功能化纳米通道中顺磁流体的传输，并构建了一种具有无标记、高灵敏度和快速响应特点的新型电化学生物传感平台。亲水性顺磁流体可以在永磁铁的帮助下迅速流过抗体固定化的纳米通道。最初发现，顺磁流体的存在会抑制电化学探针 [Fe(CN)]的氧化还原电流。这种抑制作用的机制归因于 [Fe(CN)]的受限扩散，这降低了电极表面处的浓度，以及顺磁流体的弱吸附，这增加了界面的电荷转移阻力。因此，探针的氧化还原电流可用于指示流过仿生纳米通道的顺磁流体的量。仿生纳米通道的空间位阻随着孵育相应靶标量的变化而变化，导致氧化还原电流的定量变化。通过这种方式，构建了基于顺磁流体传输的电化学生物传感平台。以糖抗原 153（CA153）为模型靶标，获得了 0.0013 U·mL 的低检测限。预计这种磁控生物电化学平台将扩展到其他应用，如基因检测、药物分析和分子鉴定。
