Key Lab for Special Functional Materials of Ministry of Education, School of Materials Science and Engineering, Henan University, Kaifeng 475004, China.
School of Physics and Electronics, Henan University, Kaifeng 475004, P. R. China.
Nanoscale. 2023 May 11;15(18):8424-8431. doi: 10.1039/d3nr00303e.
Magnetic-based microfluidic SERS biosensors hold great potential in various biological analyses due to their integrated advantages including easy manipulation, miniaturization and ultrasensitivity. However, it remains challenging to collect reliable SERS nanoprobe signals for quantitative analysis due to the irregular aggregation of magnetic carriers in a microfluidic chamber. Here, magnetic/plasmonic hybrid nanostirrers embedded with a Raman reporter are developed as capture carriers to improve the reliability of microfluidic SERS biosensors. Experimental results revealed that SERS signals from magnetic hybrid nanostirrers could serve as microenvironment beacons of their irregular aggregation, and a signal filtering method was proposed through exploring the relationship between the intensity range of beacons and the signal reproducibility of SERS nanoprobes using interleukin 6 as a model target analyte. Using the signal filtering method, reliable SERS nanoprobe signals with high reproducibility could be picked out from similar microenvironments according to their beacon intensity, and then the influence of irregular aggregation of magnetic carriers on the SERS nanoprobe could be eliminated. The filtered SERS nanoprobe signals also exhibited excellent repeatability from independent tests, which lay a solid foundation for a reliable working curve and subsequent accurate bioassay. This study provides a simple but promising route for reliable microfluidic SERS biosensors, which will further promote their practical application in biological analysis.
基于磁性的微流控 SERS 生物传感器由于其集成优势，包括易于操作、小型化和超灵敏性，在各种生物分析中具有很大的潜力。然而，由于磁性载体在微流腔中不规则聚集，因此难以收集可靠的 SERS 纳米探针信号进行定量分析。在这里，开发了嵌入拉曼报告分子的磁性/等离子体混合纳米搅拌器作为捕获载体，以提高微流控 SERS 生物传感器的可靠性。实验结果表明，磁性混合纳米搅拌器的 SERS 信号可以作为其不规则聚集的微环境示踪剂，并且通过使用白细胞介素 6 作为模型目标分析物，探索示踪剂强度范围与 SERS 纳米探针信号重现性之间的关系，提出了一种信号过滤方法。使用信号过滤方法，可以根据示踪剂强度从相似的微环境中挑选出具有高重现性的可靠 SERS 纳米探针信号，然后消除磁性载体不规则聚集对 SERS 纳米探针的影响。过滤后的 SERS 纳米探针信号在独立测试中也表现出出色的重复性，为可靠的工作曲线和随后的准确生物测定奠定了坚实的基础。本研究为可靠的微流控 SERS 生物传感器提供了一种简单但有前途的途径，将进一步促进它们在生物分析中的实际应用。
