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.
Wavelength interrogation surface plasmon resonance imaging (WSPRi) sensing has unique advantages in high-throughput imaging detection. The refractive index resolution (RIR) of WSPRi is limited to the order of 10 −6 RIU. This paper demonstrates a novel WSPRi sensing system with a wavelength scanning device of an acousto-optic tunable filter (AOTF) and a low-cost speckle-free SPR excitation source of a halogen lamp. We developed a sensitive quasi-phase extraction method for data processing. The new technique achieved an RIR of 8.84×10 −7 RIU, which is the first WSPRi system that has an RIR in the order of 10 −7 RIU. Moreover, we performed a real-time recording of the formation of the coffee ring effect during brine evaporation and enhanced the biosensor performance of SPR for the first time. We believe the higher RIR and accuracy of the system will benefit more potential applications toward exploring the biomolecules’ behaviors in biological and biochemistry studies. Graphical abstract
危险品化学品经营许可证（带存储）