Double-channel plastic optical fiber SPR sensor and preparation method thereof

Abstract

The invention discloses a plastic optical fiber surface plasma resonance sensor with a double-channel double-side-throwing structure, and belongs to the technical field of optical fiber sensing. The sensor is composed of a light source, a plastic optical fiber surface plasma resonance sensing probe with a double-side-throwing double-coating structure, a spectrograph and a computer. The optical fiber with the double-side-throwing structure is prepared from a plastic optical fiber which is soft in texture, good in flexibility and low in cost. The two polished surfaces of the plastic optical fiber with the double-side polished structure are plated with gold and silver nanoparticles respectively, so that transmission light can generate a surface plasma resonance phenomenon on the two polishedsurfaces respectively, and two resonance absorption peaks are generated at two different wavelength positions of a transmission spectrum of the transmission light respectively; therefore, dual-channelsurface plasmon resonance sensing can be realized. The surface plasma resonance sensor has the advantages of simple structure and preparation process, low cost, high mechanical strength and good integration.

Description

technical field [0001] The invention belongs to the technical field of optical fiber sensors, in particular to a dual-channel plastic optical fiber SPR sensor and a preparation method thereof. Background technique [0002] Surface plasmon resonance (SPR) is a resonance phenomenon caused by mutual coupling between the metal surface plasmon wave and the evanescent wave generated when the light wave is totally reflected, and there will be an obvious absorption peak in the transmission spectrum. This technology is very sensitive to the change of the refractive index of the measured substance on the metal surface. When the refractive index of the measured substance on the metal surface changes, it will cause the shift of the absorption peak position. By detecting the relationship between the absorption peak and the external refractive index The measurement of the refractive index of its surrounding environment can be realized. [0003] At present, SPR sensors have been widely us...

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Problems solved by technology

For example, the Chinese invention patent "a dual-core optical fiber transmissive dual-channel SPR sensor" with patent application number 201720924712.1 provides a transmissive dual-channel SPR sensor based on dual-core optical fiber, but the cost of the dual-core optical fiber used in this device is relatively high. In addition, the double-core optical fiber needs to be ground and then welded during preparation. The processing technology is complicated, and the coupling and alignment are also difficult, and it is necessary to use high-priced polarization-maintaining optical fiber fusion splicers and other equipment; China Patent Application No. 201721318193.0 The invention patent "An all-fiber microfluidic chip based on side hole and dumbbell fiber" provides an all-fiber microfluidic chip based on side hole and dumbbell fiber, which uses side hole fiber and dumbbell fiber, and the cost is relatively high. And it also requires the use of high-precision and expensive equipment; the Chinese invention patent "An Optical Fiber SPR Sensor Based on Electric Field Coupling" with patent application number 201920224690.7 provides an optical fiber SPR sensor based on electric field coupling. Multiple side throwing areas, and different film materials are plated on them to achieve multi-channel SPR sensing, but this increases the length of the device and reduces the integration

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