| Surface plasmon resonance?SPR?sensing technology is an optical detection technology,which has the advantages of label-free,high sensitivity and high throughput.The SPR biosensor has become an important detection method in the field of biology.In recent years,with the development of biotechnology research,the requirement for simultaneous and rapid detection of multiple samples has been put forward.So the SPR imaging?SPRi?technology has been proposed.SPRi takes each pixel on the 2D detector as an independent sensing unit and obtains SPR signals at different locations on the sensing surface at the same time,so as to realize simultaneous detection of various samples.At present,there are four kinds of SPR sensing technologies,including intensity-based SPR,angle-based SPR,phase-based SPR and wavelength-based SPR.Among them,wavelength-based SPR has the unique advantage of flexibly selecting the best excitation wavelength for different samples.However,wavelength-based SPR usually uses spectrometer,monochrometer or grating to realize spectral analysis and combines point scan or line scan to realize SPRi detection,which results in slow speed of SPRi and limits the application of wavelength-based SPRi sensor.Phase-based SPR has the highest sensitivity among the four kinds of SPR sensing technologies,but its dynamic range can only reach 10-4RIU,which limits the application of phase-based SPR sensing technology in simultaneous detection of various products.In this paper,we focus on improving the imaging speed of wavelength-based SPRi and the dynamic range of phase-based SPRi.Thus,we developed a series of fast wavelength-based SPRi sensing technology and experimental system.In order to further improve the spatial resolution of SPRi sensing,wavelength-based SPRi microscopy technology was developed to realize the sensing of single cells.The main contents and innovative work of this paper are listed as follows:1.We developed a series of fast wavelength-based SPRi sensing technologies and applied them to biological detection.In order to improve the detection speed of wavelength-based SPRi sensing,this paper proposes a variety of wavelength scanning methods and builds the systems.The methods include:wavelength-based SPRi sensor based on feedback tracking algorithm,wavelength-based SPRi sensor based on an adaptive spectral-dip tracking scheme,wavelength-based SPRi sensor based on two-point tracking algorithm,wavelength-based SPRi sensor based on AOTF and white light laser.All the above-mentioned wavelength-based SPRi sensors have realized real-time detection of multi-point or multi-channel specific binding reactions of biological molecules.In this paper,wavelength-based SPRi is also applied to blood typing detection to achieve rapid and accurate ABO typing.2.We developed a phase-based SPR sensor with large dynamic range based on spectral interference.In order to increase the dynamic range of phase SPR,a large dynamic-range phase-based SPR sensing technology based on spectral interference is proposed in this paper.Wide-spectrum light is used as excitation source,and wave plate is exploited to delay the phase of p-and s-light.Phase information is obtained through SPR interference spectrum to realize sample sensing.The experimental results show that the sensitivity and dynamic range of the system are1.3×10-7RIU?2.96×10-2RIU,respectively.We also developed a phase-based SPRi sensing technology with large dynamic range based on spectral interference.The incident light is scanned by an AOTF,and the sensing surface is imaged by CCD at different wavelengths.The interference spectrum of different locations on the sensing surface is obtained.And the phase information is obtained from the interferometric spectrum so as to realize the simultaneous detection of various samples.3.We developed a SPRi microscopy technology based on wavelength scanning.Compared with the intensity-based SPRi microscopy,the wavelength-based SPR microscopy has the advantages of high sensitivity and large dynamic range.In this paper,we propose a system which combines wavelength-based SPR sensing technology with microscopy technology to monitor the adherence of a single cell under different external stimulus.Finally,we summarized the main works of this paper and discussed the related problems should be solved in future.And then we discussed how to further optimize the detection system.The future work is also introduced,including the construction of phase-based SPRi system with large dynamic range based on spectral interference;the construction of wavelength-based SPR microscopy using AOTF as scanning device which can image cells while sensing cell secretion;and the construction of wavelength-based SPR sensor based on TIFER microscopy. |
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