The detection principle of nanopore sensors relies on measuring changes in electrical signal as analyte molecules translocate through a nanoscale pore. There are two challenges with this experimental construct when using nanopores for quantitative sensing with low detection limits in complex samples. The first is getting the analyte to the nanopore in a reasonable time frame and the second is other species in the sample also translocating through the nanopore and generating erroneous signals. We have developed a nanopore blockade sensor that alleviates the limitations of diffusion-limited mass transport and non-specific signals. Antibody-modified magnetic nanoparticles are utilized to deliver analytes of interest extracted from sample to an array of antibody-modified nanopores under a controlled electromagnet, resulting in long-term nanopore blocking events due to the formation of sandwiched immunocomplexes. Herein, this study reports on understanding some of important parameters in determining the performance of nanopore blockade sensing system, where prostate-specific antigen (PSA) is used as a model analyte. We describe the characterization of nanopore blockade sensing of PSA by (1) tuning on/off the electromagnet, (2) varying nanopore number in a nanopore chip, and (3) deploying the sensor in human plasma. Results show that magnetophoresis effectively facilitates active delivery and selective sensing of PSA to the nanopore. Nanopore chips with a larger number of nanopores are shown to receive more nanopore blockades for a given concentration of analyte. Furthermore, identifiable blockade events accounted for successful detection of PSA in plasma, indicate the high specificity of the sensing system.

纳米孔传感器的检测原理依赖于测量分析物分子通过纳米级孔易位时电信号的变化。当使用纳米孔在复杂样品中以低检测限进行定量传感时，这种实验结构存在两个挑战。第一个是在合理的时间范围内将分析物送入纳米孔，第二个是样品中的其他物质也通过纳米孔移位并产生错误信号。我们开发了一种纳米孔阻塞传感器，可减轻扩散受限的质量传输和非特异性信号的限制。抗体修饰的磁性纳米粒子用于将从样品中提取的目标分析物输送到受控电磁铁下的抗体修饰纳米孔阵列，由于形成夹层免疫复合物，导致长期纳米孔阻塞事件。在此，本研究报告了了解确定纳米孔阻断传感系统性能的一些重要参数，其中前列腺特异性抗原 (PSA) 用作模型分析物。我们通过 (1) 调节电磁铁的开/关，(2) 改变纳米孔芯片中的纳米孔数量，以及 (3) 在人体血浆中部署传感器来描述 PSA 的纳米孔阻塞传感的特性。结果表明，磁泳有效地促进了 PSA 到纳米孔的主动递送和选择性传感。对于给定浓度的分析物，具有大量纳米孔的纳米孔芯片显示出接收更多的纳米孔阻塞。此外，可识别的阻断事件解释了血浆中 PSA 的成功检测，