Simultaneous immunoassays of dual prostate cancer markers using a SERS-based microdroplet channel

The simultaneous detection of multiple biomarkers plays an important role in the accurate diagnosis of cancer. In this study, we developed a novel, surface-enhanced Raman scattering (SERS)-based microfluidic device for the simultaneous detection of free prostate-specific antigen (f-PSA) and total PSA (t-PSA) markers. A fully automatic droplet-based microfluidic platform for the rapid and sensitive detection of f-PSA and t-PSA was designed. Magnetic immunocomplexes were aligned on one side of the channel using a permanent magnet embedded in the microfluidic device, and parent microdroplets containing magnetic immunocomplexes and supernatant solutions were split into two smaller daughter droplets at the Y-shaped junction of the channel. Then, Raman signals of sequential droplets including supernatant solutions were measured for the quantitative analysis of the PSA markers. Two parallel microfluidic channels were designed and fabricated for the simultaneous detection of f-PSA and t-PSA. Our results showed a good linear response for both PSA markers in the range from 0.05 to 100 ng mL -1 . The limits of detection were estimated to be below 0.1 ng mL -1 for both the f-PSA and t-PSA. This SERS-based assay in a microfluidic channel was completed in 10 min without any manual incubation and washing steps. Our method is a very promising clinical tool for PSA-based screening test of prostate cancer.

多种生物标志物的同时检测对于癌症的准确诊断具有重要作用。在这项研究中，我们开发了一种新型的基于表面增强拉曼散射 (SERS) 的微流体装置，用于同时检测游离前列腺特异性抗原 (f-PSA) 和总 PSA (t-PSA) 标记物。设计了一种基于液滴的全自动微流控平台，用于快速、灵敏地检测f-PSA和t-PSA。使用嵌入微流体装置中的永磁体将磁性免疫复合物排列在通道的一侧，并且含有磁性免疫复合物和上清液的母体微滴在通道的Y形连接处分裂成两个较小的子体液滴。然后，测量包括上清液在内的连续液滴的拉曼信号，以对 PSA 标记物进行定量分析。设计并制造了两个平行的微流体通道，用于同时检测 f-PSA 和 t-PSA。我们的结果显示，两种 PSA 标记物在 0.05 至 100 ng mL -1 范围内具有良好的线性响应。 f-PSA 和 t-PSA 的检测限估计低于 0.1 ng mL -1。这种基于 SERS 的微流体通道检测在 10 分钟内完成，无需任何手动孵育和清洗步骤。我们的方法是基于 PSA 的前列腺癌筛查测试的非常有前途的临床工具。