Broadband interference type photoelectrode biomolecular sensor of graphene oxide fiber bragg grating

Abstract

The invention relates to a photoelectrode biomolecular sensor, in particular to a broadband interference type photoelectrode biomolecular sensor and method of a graphene oxide fiber bragg grating. Thesensor comprises an optical fiber core, an optical fiber cladding, an optical fiber coating layer, and a large-angle inclined fiber bragg grating arranged in the middle of the optical fiber core; coating layers of the middle section and the rear section of an optical fiber are completely removed, the tail end surface of the rear section of the optical fiber is plated with a silver reflecting film, the distance between the rear end of the large-angle inclined optical fiber grating and the silver reflecting film at the tail end of the optical fiber ranges from 30 mm to 60 mm, and an optical fiber micro Michelson interference cavity is formed. A silane layer, a nano gold shell particle layer, a graphene oxide layer and a biomolecule sensitive layer are arranged on the cladding surface from the starting end of the large-angle tilted fiber bragg grating to the tail end of the optical fiber. The photoelectrode biomolecular sensor structure can be used to increase the action distance betweenLSPR excited by a light wave evanescent place and biomolecules, is convenient to integrate and apply, has very high robustness, and can be applied to the fields of biomedicine, life science, environmental monitoring and the like.

Description

technical field [0001] The invention relates to an optode biomolecular sensor, in particular to a graphene oxide optical fiber grating broadband interference optode biomolecular sensor and a method. Background technique [0002] Graphene has excellent characteristics such as large specific surface area, high electron mobility, high conductivity, and biomolecular affinity. Its oxide, graphene oxide, also contains abundant oxygen-containing functional groups such as carboxyl and hydroxyl groups. It is beneficial for covalent or non-covalent linking with biomolecules, etc. Therefore, the biochemical sensing technology that combines two-dimensional materials such as graphene and graphene oxide with traditional electrochemical, piezoelectric, and optical sensors, such as surface plasmon resonance sensors and various types of optical fiber sensors, has been obtained. Extensive research. [0003] In the field of biochemical detection, the Surface Plasmon Resonance (SPR) sensor is...

AI Technical Summary

Problems solved by technology

At present, most commercialized LSPR sensors are based on the Kretschmann prism coupling structure for angle detection, such as figure 1 As shown, but this type of LSPR sensor is large in size, long in scan time, and expensive

Because optical fibers have the advantages of corrosion resistance, anti-electromagnetic interference, small size, and remote sensing, various optical fiber materials and devices can be used as excitation platforms to realize the miniaturization of LSPR sensors, such as: based on multimode quartz (or polymer materials ) optical fiber, different-core structured optical fiber or photonic crystal optical fiber, etc., these all belong to the type of pure optical fiber LSPR sensor, but most of them have a main problem: the resonance bandwidth of the LSPR peak is generally in the tens of nanometers to one hundred between many nanometers, so the quality factor (i.e., Q-value) of the sensor is low

[0006] However, the common problems existing in the above-mentioned existing optical fiber LSPR technologies are: 1) most of them adopt the method of detecting transmission spectrum, and the light source and spectrum analyzer are respectively located at both ends of the sensor, which is not convenient for actual integration and use; 2) nanometer The binding ability of gold particles to biomolecules is relatively weak (about 1pg / mm 2 ), resulting in a small detection range of biochemical sensors; 3) traditional optical fiber SPR / LSPR sensors are based on the principle of SPR / LSPR resonance wavelength shift or resonance absorption power change to detect the amount of target biomolecules, while for optical fiber surface It is difficult to monitor the dynamic process of the reaction (combination) between the sensitive layer of biomolecules and biomolecules in real time

This is because the biomolecular reaction (combination) process is a slow variable, and the resonance wavelength shift or the change of the resonance absorption power caused by a short period of time is very weak, and the resolution of the current spectrometer (1pm) cannot Signal noise such as such a subtle change in the resonance wavelength of the distribution, or a weak fluctuation in the intensity of the light source, will overwhelm the change in the resonance absorption power of the LSPR

Other individual problems are: 1) The LSPR spectra excited by pure fiber-based LSPR sensors are all in a certain wavelength range between 500nm and 900nm, and the bandwidth is generally >50nm, such as image 3 Shown is a schematic diagram of pure fiber-optic LSPR sensors increasing with the concentration of substances to be measured, so the Q value of the sensor is very low, and most of them need to corrode or grind the fiber cladding to excite LSPR, thus reducing the mechanical strength and Robustness; 2) The cladding modes of the small-angle TFBG-LSPR sensor in the communication band (1500nm~1600nm) resonance spectrum envelope are too dense and numerous, and it is inconvenient to accurately locate the LSPR peak in practical applications

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