Surface Plasmon Resonance Sensing System And Its Enhanced Fluorescence Method

Surface plasmon resonance(SPR)technology,as a commonly used detection method in the field of biosensing,is widely used in clinical diagnosis and other fields with its own technological advantages.Compared to SPR real-time detection,unlabeled,and highly sensitive detection characteristics,fluorescence analysis technology also has good specificity and selectivity.With the increasing research demand in the field of biosensing for complex samples and low concentration detection,the fluorescence signals measured in traditional fluorescence analysis detection are susceptible to interference from background fluorescence signals.At the same time,the fluorescence signals emitted in free space have anisotropy,which leads to lower detection efficiency of the overall fluorescence signal.This means that the sensitivity of fluorescence detection methods needs to be further improved.In summary,this project revolves around the research of biological sensing and enhanced fluorescence detection based on the SPR principle.The specific research content is as follows:Firstly,SPR technology is suitable for studying the binding kinetics between various biomolecules,ranging from drug molecule screening and development to cell virus detection.In response to the current demand for SPR kinetics research,this paper constructs a 1:1 reaction SPR molecular dynamics finite element simulation model in microchannels,and establishes a multi-structure coupling model of the target to be tested,molecular binding layer,gold film,and optical transport layer,The complete process simulation from biological information to optical information has been achieved,and SPR kinetic reaction experiments can be rehearsed without conducting experiments.In addition,the global local coupled SPR dynamic fitting algorithm proposed in this article can accurately extract dynamic parameters from experimental data.The results show that the fitting effect of this algorithm is consistent with that of commercial analysis software algorithms.Furthermore,in the fitting of low concentration nucleic acid SPR data,the fitting residual of the coupled algorithm is only half of that of the commercial algorithm.Secondly,this article proposes a prism coupled integrated SPR sensor and opto electromechanical integrated detection instrument based on matching film technology to address the issues of limited functionality and poor scalability of current commercial SPR instruments.The instrument is compatible with various SPR modulation methods such as angle modulation,light intensity modulation,and wavelength modulation.The proposed symmetrical bidirectional screw angle modulation motion structure can achieve angle adjustment within the range of 25 ° to 80 °,with an angle scanning accuracy of 1 ‰ degree.In addition,the integrated microarray matched film SPR sensor chip prepared using photolithography and soft film imprinting technology not only ensures high sensitivity sensing,but also shortens the waiting time required for surface plasmon resonance imaging(SPRI)experiments,and effectively solves the problems of poor imaging consistency and chip disassembly difficulties in traditional SPR chips.Finally,based on the self-made multifunctional SPR instrument,two fluorescence spectroscopy detection systems,surface plasmon enhanced field fluorescence spectroscopy(SPFS)and surface plasmon coupled emission fluorescence(SPCE),were established in this paper,and fluorescence enhancement methods based on the SPR principle were studied.The experimental results show that the detection signals of SPCE and SPFS are approximately 6.5 and 4.4 times enhanced compared to traditional fluorescence.In addition,in response to the demand for detection of biological samples in solution,using sheep anti mouse Ig G as the detection object,the SPCE immune detection method was combined with microfluidic technology.With the flexible fluid driving characteristics of microfluidic technology,the gradient sensing detection of SPCE immune response Ig G protein concentration in aqueous medium was finally achieved,with a detection limit of 1.45 n M.