Research On Instrumentation Of A Surface Plasmon Resonance Sensing Method

Surface plasmon resonance(SPR) is a technology to detect refractive index byusing optical method.Sensors based on SPR technology can monitor intermolecularinteractions in real-time.It can give high analysis speed,high sensitivity,label-freedetection and only need a small amount of sample, has shown a good prospect ofapplication. Compared with traditional analysis system, advantage of surface plasmonresonance technology is obvious, and has been widely used in the fields of physics,chemistry, biology, environmental protection.Compared with traditional SPR technology, long range SPR technology has highersensititity and higher penetration depth of electromagnetic field, higher resonance peakdepth, so it has been widely developed in the field of scientific research.While inpractical application, it is hard to popularize because of its special film matchingconditions: the analyte and the the refractive index of the buffer layer must be similar.In order to improve the applicability of the long-range SPR technology, further improvethe penetration depth of electromagnetic field and the resonance peak depth, we proposea symmetric long-range SPR technology.SPR sensors based on wavelength and angular spectrum have more linearresponses and wider dynamic ranges, and are hence suitable for quantitativedetection.We choose angular spectrum to be our detection method. In experiment, wefound that symmetrical LRSPR has higher resonance peak depth and sensitivity, thusreducing the distance between optical detector and the SPR excitation module, therequirements of the optical detector, the system is very suitable for miniaturization. Atthe same time, we also found the lack of laboratory measurement system, namely (1)mechanism structure is not stable enough (2) injection system is not perfect (3) sensitiveto fluctuations of environment temperature(4) building the system repetitively consumesa lot of time. In order to solve these problems and also to enhance portability, toimprove the detecting throughput, we conducted a long range SPR prototype system.The system has the integrated mechanism structure design, the microfluidic system,reference flowcell channel, a friendly software interface design and its processingalgorithm has been optimized. After the experiment, the resolution of the system canreach6.1×107RIU, impact of fluctuations in outside temperature is highly reduced.The development of this prototype system is successful and met the design requirements,made an important step of instrumentation of LRSPR technology.