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Research Of Optical Fiber Surface Plasmori Resonance PH Sensor

Posted on:2016-04-03Degree:MasterType:Thesis
Country:ChinaCandidate:T T LiFull Text:PDF
GTID:2298330467494084Subject:Measuring and Testing Technology and Instruments
Abstract/Summary:PDF Full Text Request
Surface Plasmon Resonance technology has been widely used because of theadvantages of immunity to electromagnetic interference, remarkable sensitivity, andso on. It has been used in biology, chemistry, pharmaceutical analysis, environmentalmonitoring, food testing and other areas. The optical fiber sensor based on surfaceplasmon resonance has more advantages, such as small sensing probe,flexibleshape,corrosion resistance, high temperature and so on. In recent years, it has become a hotpoint. SPR technology combined with other techniques, which can further improvethe application of SPR technology has opened up broad prospects.Nowadays, pH indicator, pH paper, pH meter, sensitive glass electrode and membrane potential methods are widely used in the areas of chemistry, biomedical as wellas environmental science. Nevertheless, those methods have plenty of shortcomings, such as large volume of measuring electrode and low accuracy of pH measurement, which can be tackled with by using optical fiber surface Plasmon resonance pH sensor. This pH sensor uses quartz fiber with a diameter of400μm as the fiber optical probe. The end cladding of a length L is removed and the gold layer of a thickness of50nm isplated on the fiber core. Besides, the pH-sensitive smart hydrogel, which is Polyacrylamide hydrogel, is coated outside the gold layer. The change in pH of the fluid aroundthe probe causes the swelling/shrinkage of the hydrogel layer resulting in the changein its refractive index. The sensor works on wavelength interrogation method. Thechange in refractive index causes a change in the resonance wavelength in thetransmitted spectrum. Experimental results show a blue shift in the resonancewavelength on the increase in the pH of the aqueous solution. The sensor operates inthe low and high pH range. The influence of environmental temperature (in16–28℃range) on its performance is found to be negligible. Further, the sensorpossesses short response time, stability and remarkable sensitivity. The detection accuracy of the sensor increases as the pH of the fluid increases. The additionaladvantages of the present probe are small size probe, no effect of sourcefluctuation/intensity reduction on its performance because the sensor is based onwavelength interrogation and its low cost because the operational wavelength range isin visible region.
Keywords/Search Tags:SPR, Sensor, Fiber, MATLAB Simulation, pH
PDF Full Text Request
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