The signal amplification methods of surface plasmon resonance (SPR) are mainly with sample selectivity. Herein proposed is a liquid core coupling SPR sensing method with adjustable sensitivity and universal applicability. A liquid core coupling unit and based on which a wavelength interrogation SPR sensor have been designed and constructed, in which a conventional chip could be used with an ingenious design and the sensitivity can be adjusted by changing the liquid core refractive index. The experimental data revealed that the sensitivity can be enhanced for 7.8 times by decreasing the liquid core refractive index from 1.5174 to 1.4502. The real applicability was validated by determination of carcinoembryonic antigen (CEA) with the signal intensity of the early stage colon cancer patient clearly up-regulated for nearly 18 folds compared with the healthy. It exhibited an adequate sensitivity, and further considering its simplicity avoiding the troublesome analysis process and/or chip preparing procedure, and extendibility to SPR imaging, the proposed method would be promising for medical diagnostics, food safety, environmental monitoring, and so on.

表面等离子体共振（SPR）的信号放大方法主要具有样品选择性。本文提出了一种灵敏度可调，通用性强的液芯耦合SPR传感方法。一种液芯耦合单元，并以此为基础设计和构造了波长询问SPR传感器，在该单元中，可以巧妙地使用常规芯片，并可以通过改变液芯折射率来调节灵敏度。实验数据表明，通过将液芯折射率从1.5174降低到1.4502，可以将灵敏度提高7.8倍。通过确定癌胚抗原（CEA）验证了实际的适用性，与健康人相比，早期结肠癌患者的信号强度明显上调了近18倍。它具有足够的灵敏度，并且进一步考虑了其简单性，避免了麻烦的分析过程和/或芯片制备程序，以及对SPR成像的可扩展性，因此该方法在医学诊断，食品安全，环境监测等方面将很有希望。