Modification, Application And Instrumental Development Of Fiber Optic Surface Plasmon Resonance Sensors

Surface plasmon resonance is an optical phenomenon,in which evanescent electromagnetic field of the incident light is coupled to the collective oscillations of the conductive electrons in metal film.Based on surface plasmon excitation,SPR sensors could distinguish the changes in the refractive index of surrounding environment on the sensors by analyzing the changes in the resonance angle,resonance wavelength or resonance intensity.Therefore,it can be used in various fields including environmental monitoring,food safety,biological science and so on.The SPR sensors which use fiber optic as coupler are called fiber optic SPR sensors.These SPR sensors attracted a lot of concerns in recent years because of their advantages such as small size,portability,anti-electromagnetic interference and pluggable.In this paper,to realize actual sample detection using fiber optic SPR sensors and the commercialization of fiber optic SPR,we focused on melamine(MEL)detection using fiber optic SPR sensors by competitive inhibition assay and the development of multichannel fiber optic – prism SPR spectrometer.The main conclusions are drawn as follows:(1)Melamine detection using fiber optic SPR sensors by competitive inhibition assayWe fabricated gold film fiber optic SPR sensors which has high sensitivity(1873.7nm/RIU)using polydopamine(PDA)accelerated electroless plating technique.After connecting with MEL antigen using 11-mercaptoundecanoicacid,we detected the mixture of MEL antibody and sample for the MEL concentration by competitive inhibition assay.The detection range is 2-200 ng/mL.Meanwhile,we also detected the real milk sample and found that the recovery was 85%-120%,which showed the promising application potentiality of fiber optic SPR sensors.(2)The development of multichannel fiber optic – prism SPR spectrometerBased on the reflection type fiber optic SPR sensors,we designed eight channels fiber optic SPR spectrometer.We established optics system for eight channels simultaneous detection using optical multiplexer.And at meantime we built tandem liquid system using peristaltic pump,all-in-one sensors and micro flow cells.Besides, for the smaller size,we did further design for the above components.Finally,multichannel fiber optic – prism SPR spectrometer was finished with project partner's help.The spectrometer was tested and the results were good.