Self-accurate fiber-optic surface plasmon resonance biochemical detection sensor with dual modulation modes

Abstract

The invention provides a double-modulation-mode self-precision optical fiber surface plasma resonance biochemical detection sensor and belongs to the technical field of optical fiber sensing. The sensor adopts a terminal reflective sensing structure. According to the invention, the end face of a fiber core of a plastic-clad multimode fiber with the core diameter being 400-600 m and numerical aperture being not less than 0.24 is polished, and the polished fiber core end-face undergoes sputtering of more than 200 nm of a silver film to form a reflecting mirror surface; and two sections of coating layers and cladding layers on the multimode fiber are stripped to form two sensing channels of 5-10 mm long. Gold nano-spheres are fixed on the surface of one sensing channel, and silver-ITO two-layered films are sputtered in the order of silver-ITO onto the surface of the other sensing channel, wherein thickness of the silver layer is 35-45 nm, and thickness of the ITO layer is 5-15 nm. By a simple sputter coating technology and a layer-by-layer self-assembly method, double-modulating signal demodulation is realized, and precision influence generated by a single modulation mode is avoided.

Description

technical field [0001] The invention belongs to the technical field of optical fiber sensing, and relates to a dual-modulation optical fiber surface plasma resonance biochemical detection sensor with self-accurate function. Background technique [0002] At present, the dual-channel biochemical sensors using the surface plasmon resonance principle mostly adopt the prism coupling structure. This type of sensor has complex structure, large volume, and high production cost, so it is difficult to form a wide application in industrial production; although there are currently multi-layer metal alternating film systems Surface plasmon resonance sensors have emerged, but most of them are single-channel structures. In the sensing and detection of biochemical samples, they are easily affected by factors such as temperature or the change of the refractive index of the sample solution body and sample volatilization. The sensors do not have compensation capabilities. Accuracy is poor. Ho...

AI Technical Summary

Problems solved by technology

[0002] At present, the dual-channel biochemical sensors using the surface plasmon resonance principle mostly adopt the prism coupling structure. This type of sensor has complex structure, large volume, and high production cost, so it is difficult to form a wide application in industrial production; although there are currently multi-layer metal alternating film systems Surface plasmon resonance sensors have emerged, but most of them are single-channel structures. In the sensing and detection of biochemical samples, they are easily affected by factors such as temperature or the change of the refractive index of the sample solution body and sample volatilization. The sensors do not have compensation capabilities. poor accuracy

However, the existing dual-channel optical fiber sensors based on the principle of surface plasmon resonance mostly use the method of modulation wavelength by coating, the modulation method is single, and the detection accuracy is poor.

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