| Surface plasmon resonance (SPR) monitor instrument has the advantage of high-sensitivity, fast detection, less sample needed and label-free analysis. It can be widely used in chemistry, biometrics, environmental monitor, food detection, clinic diagnosis, and medicine etc. However, most SPR instruments have the disadvantage of complex structure, huge physical volume, and high cost. The disadvantage limits its application in field monitor and real-time analysis. As a result, developing a small and low-cost SPR monitor instrument will spread SPR technique using in each area. It will bring huge social benefits and economic benefits.This research carefully analyses the application area, developing trend and sensor principle of the SPR monitor instrument. We developed a set of small SPR monitor instrument independently. The instrument consists of a SPR sensor, a sampling system with tiny and constant flow, a data acquisition probe circuit, and analysis processing software. The SPR sensor adopts non-scanning modulation structure with broad beam. This modulation is based on the traditional scanning modulation with moving parts. But it reduces the physical volume of SPR sensor. The sampling system with tiny and constant flow consists of high precision pump and multi-position micro-electric valve. This system can control the speed of sample and choose different sample. All the measuring process is auto finished. The data acquisition probe circuit and analysis processing software provide the function of data acquisition and analysis processing for SPR instrument.Ethanol and dextrose solutions of different concentration are measured by our small SPR instrument. The result presents that the sensitivity reaches approximately 10-5RIU, the minimum concentration of dextrose solution can be detected is 0.1%, the measuring error can be controlled in 20%. Experiments results show the instrument has good performance of repeatability and stability. |
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