阅读说明：本技术 分子印迹荧光光纤传感器及其构建方法、荧光检测方法 (molecular imprinting fluorescence optical fiber sensor, construction method thereof and fluorescence detection method ) 是由 黄庆达 赖家平 于 2019-08-30 设计创作，主要内容包括：本发明公开了一种分子印迹荧光光纤传感器及其构建方法、荧光检测方法,所述传感器包括激光光源、Y型光纤、石英光纤、法兰适配器和光纤光谱仪,激光光源、Y型光纤和光纤光谱仪依次相连,石英光纤修饰含有分子印迹微球的凝胶膜,所述Y型光纤与石英光纤之间通过法兰适配器相连接；激光光源发射出的激光通过Y型光纤传递到石英光纤上的凝胶膜,凝胶膜的荧光信号反射回Y型光纤,由Y型光纤传递到光纤光谱仪。本发明的传感器为可拆卸式的传感器,使得光纤探头可以替换,以便在现场分别进行多目标的快速检测,能够运用于环境水体中抗生素的现场快速监测,并且在使用结束后可以轻松破坏光纤探头修饰的传感膜,光纤探头得以回收,减少不必要的资源浪费。(The invention discloses a molecularly imprinted fluorescent optical fiber sensor, a construction method thereof and a fluorescence detection method, wherein the sensor comprises a laser light source, a Y-shaped optical fiber, a quartz optical fiber, a flange adapter and an optical fiber spectrometer, the laser light source, the Y-shaped optical fiber and the optical fiber spectrometer are sequentially connected, the quartz optical fiber modifies a gel film containing molecularly imprinted microspheres, and the Y-shaped optical fiber and the quartz optical fiber are connected through the flange adapter; laser emitted by the laser source is transmitted to the gel film on the quartz optical fiber through the Y-shaped optical fiber, and a fluorescence signal of the gel film is reflected back to the Y-shaped optical fiber and is transmitted to the optical fiber spectrometer through the Y-shaped optical fiber. The sensor is detachable, so that the optical fiber probe can be replaced, multi-target rapid detection can be respectively carried out on site, the sensor can be applied to on-site rapid monitoring of antibiotics in environmental water, and the sensing film modified by the optical fiber probe can be easily damaged after the use is finished, so that the optical fiber probe can be recycled, and unnecessary resource waste is reduced.)

1. The molecular imprinting fluorescence optical fiber sensor is characterized by comprising a laser light source, a Y-shaped optical fiber, a quartz optical fiber, a flange adapter and an optical fiber spectrometer, wherein the laser light source, the Y-shaped optical fiber and the optical fiber spectrometer are sequentially connected, the quartz optical fiber modifies a gel film containing molecular imprinting microspheres, and the Y-shaped optical fiber and the quartz optical fiber are detachably connected through the flange adapter;

The laser emitted by the laser source is transmitted to the gel film on the quartz optical fiber through the Y-shaped optical fiber, and the fluorescence signal of the gel film is reflected back to the Y-shaped optical fiber and transmitted to the optical fiber spectrometer through the Y-shaped optical fiber.

2. The molecularly imprinted fluorescent fiber sensor of claim 1, further comprising a dark box, wherein the end of the Y-shaped fiber connected with the quartz fiber, the quartz fiber and the flange adapter are all arranged in the dark box.

3. The molecularly imprinted fluorescent fiber sensor of claim 1, further comprising a computer, wherein the fiber spectrometer is connected to the computer.

4. the molecularly imprinted fluorescent fiber sensor of any one of claims 1 to 3, further comprising a filter disposed between the Y-shaped fiber and the fiber spectrometer, wherein the Y-shaped fiber is connected to the fiber spectrometer through the filter.

5. a method for constructing the molecularly imprinted fluorescent optical fiber sensor according to any one of claims 1 to 4, wherein the method comprises the following steps:

synthesizing molecularly imprinted polymer nano-microspheres;

Dispersing a part of synthesized molecularly imprinted polymer nano-microspheres in water to prepare molecularly imprinted microsphere aqueous dispersion;

transferring part of the prepared dispersion liquid into a small conical bottle, adding polyethylene glycol methyl diacrylate and 2-hydroxy-2-methyl propiophenone, magnetically stirring for a period of time, and degassing to obtain a semitransparent gel film pre-polymerization liquid;

Inserting the quartz optical fiber into a hollow glass tube, injecting a part of gel film pre-polymerization liquid into the bottom end of the hollow glass tube, carrying out photopolymerization under an ultraviolet lamp for a period of time, and taking out the quartz optical fiber to obtain the quartz optical fiber for modifying the gel film containing the molecularly imprinted microspheres;

The laser light source, the Y-shaped optical fiber and the optical fiber spectrometer are sequentially connected, and the quartz optical fiber for modifying the gel film containing the molecular imprinting microsphere is connected with the Y-shaped optical fiber through the flange adapter.

6. The construction method according to claim 5, wherein the synthetic molecularly imprinted polymer nanospheres specifically comprise:

Filling template molecule powder into a round-bottom flask, adding acetonitrile solution to perform ultrasonic full dissolution, adding methacrylic acid, divinylbenzene and azobisisobutyronitrile, performing ultrasonic full dissolution, introducing nitrogen for a period of time, and sealing the round-bottom flask by using an adhesive tape;

Putting the round-bottom flask into a constant-temperature water bath for reaction to obtain a white precipitation polymer, namely the molecularly imprinted polymer nano-microsphere;

Centrifuging to remove the solvent in the round-bottom flask, washing to remove the unreacted organic solvent, and eluting the template molecules on the molecularly imprinted polymer nanospheres;

putting the molecular imprinting polymer nano-microspheres in a vacuum drying oven overnight to obtain the substitute molecular imprinting polymer.

7. The construction method according to claim 6, wherein the washing step is to remove the unreacted organic solvent and elute the template molecule on the molecularly imprinted polymer nanosphere, and specifically comprises the following steps:

repeatedly washing with a mixed solution of methanol and water to remove unreacted organic solvent;

Eluting the template molecules on the molecularly imprinted polymer nano-microspheres on a shaking table by using a mixed elution solution of methanol and acetic acid until the template molecules of the supernatant of the eluent cannot be detected on an ultraviolet spectrophotometer, and washing away the acetic acid by using methanol.

8. The building method according to any one of claims 5 to 7, wherein the silica optical fiber is inserted into the hollow glass tube, specifically:

And sleeving the quartz optical fiber into a conical plastic mold, and inserting the conical plastic mold into the hollow glass tube to fix the quartz optical fiber in the center of the hollow glass tube.

9. the method according to any one of claims 5 to 7, wherein the distance between the silica optical fiber and the bottom end of the hollow glass tube is adjusted to 0.2cm to 0.3cm after injecting a part of the gel film pre-polymerization solution into the bottom end of the hollow glass tube.

10. A fluorescence detection method based on the molecularly imprinted fluorescent optical fiber sensor according to any one of claims 1 to 4, wherein the method comprises:

Absorbing the detection solution into a centrifugal tube, putting the quartz optical fiber into the centrifugal tube for soaking, and performing ultrasonic absorption for a period of time;

After adsorption is finished, taking out the quartz optical fiber, soaking the quartz optical fiber in deionized water, and washing away unadsorbed residual adsorption liquid;

The processed quartz optical fiber is connected into the whole instrument through the flange adapter, laser emitted by the laser source is transmitted to the gel film on the quartz optical fiber through the Y-shaped optical fiber, a fluorescence signal of the gel film is reflected back to the Y-shaped optical fiber and is transmitted to the optical fiber spectrometer through the Y-shaped optical fiber, and therefore fluorescence detection is achieved.

Technical Field

the invention relates to a molecularly imprinted fluorescent optical fiber sensor, a construction method thereof and a fluorescence detection method, and belongs to the field of detection of antibiotics in a water environment.

background

In recent years, with the rapid development of light technology, various light sensors (FOS) have come into play. This is because FOS has several major advantages: first, FOS is characterized by miniaturization. The sensing part is flexible and light, has good space adaptability and biocompatibility, and is suitable for real-time and on-line monitoring of clinical medicine, organisms and various environmental water bodies; secondly the FOS has the advantages of wide monitoring object and great flexibility. Particularly, the development of sensing membrane technologies such as a molecular imprinting membrane, a polymer membrane, a Sol-gel membrane and other related membrane technologies provides more feasible methods for preparing the optical fiber sensing membrane. Thirdly, the FOS has the characteristics of electromagnetic interference resistance, large transmission information quantity, small optical energy transmission loss, strong environment adaptability and the like; fourth, FOS can achieve self-referencing, requiring an additional reference electrode compared to electrochemical sensors. The FOS can obtain stable optical information by utilizing self-reference, and the instability of a sensing probe is avoided.

molecular Imprinting Technique (MIT) refers to a process of preparing a Polymer having specific selectivity for a specific target molecule (template molecule), and the prepared Polymer is called a Molecular Imprinted Polymer (MIP). The molecularly imprinted polymer is an artificial antibody tailored as a target molecule, is known to have the characteristics of high selectivity, severe environment resistance and the like, is widely applied to various fields such as solid phase extraction, biomimetic sensors, enzyme simulation catalysis and the like, and has very wide application in environmental detection.

Molecularly imprinted fiber optic sensors (OFS-MIPs) apply MIPs as a sensitive material to fiber optic sensors. Generally, the MIPs are used as a sensing layer of an optical fiber sensor, light emitted by a light source is transmitted to the MIPs sensing layer through an optical fiber by the optical fiber sensor, the MIPs sensing layer interacts with an external measured substance, so that the optical characteristics of an optical signal are changed, a biochemical signal is converted into an optical signal, and the optical signal enters a signal demodulator through the optical fiber to perform qualitative/quantitative analysis on the measured substance. The coupling of the molecular imprinting and the optical fiber sensor at present specifically comprises: in-situ polymerization, adhesive surface coating, surface modification, capillary coupling and the like. The OFS-MIPs have the MIPs specificity recognition function, and meanwhile, the OFS-MIPs have the advantages of good stability, high sensitivity, simplicity in manufacturing, low cost, portability, low-consumption transmission, electromagnetic interference resistance, safety and the like of the optical fiber sensor, can realize real-time and remote monitoring by utilizing a modern communication technology, and have great development potential. Currently, the molecular imprinting optical fiber sensing technology is applied to a plurality of fields such as clinical analysis, food, environment and the like.

disclosure of Invention

the invention provides a molecularly imprinted fluorescent optical fiber sensor, which is a detachable sensor, so that an optical fiber probe can be replaced, multi-target detection can be respectively carried out on the site, the sensor can be applied to on-site rapid detection of antibiotics in environmental water, the sensing film modified by the optical fiber probe can be easily damaged after the use, the optical fiber probe can be recovered, and unnecessary resource waste is reduced.

the second purpose of the invention is to provide a construction method of the molecularly imprinted fluorescent optical fiber sensor.

the third purpose of the invention is to provide a fluorescence detection method of the molecularly imprinted fluorescent optical fiber sensor.

The first purpose of the invention can be achieved by adopting the following technical scheme:

A molecular imprinting fluorescence optical fiber sensor comprises a laser light source, a Y-shaped optical fiber, a quartz optical fiber, a flange adapter and an optical fiber spectrometer, wherein the laser light source, the Y-shaped optical fiber and the optical fiber spectrometer are sequentially connected, the quartz optical fiber modifies a gel film containing molecular imprinting microspheres, and the Y-shaped optical fiber and the quartz optical fiber are detachably connected through the flange adapter;

The laser emitted by the laser source is transmitted to the gel film on the quartz optical fiber through the Y-shaped optical fiber, and the fluorescence signal of the gel film is reflected back to the Y-shaped optical fiber and transmitted to the optical fiber spectrometer through the Y-shaped optical fiber.

furthermore, the optical fiber monitoring device further comprises a dark box, wherein one end of the Y-shaped optical fiber connected with the quartz optical fiber, the quartz optical fiber and the flange adapter are all arranged in the dark box.

further, the device also comprises a computer, and the fiber spectrometer is connected with the computer.

The optical fiber spectrometer further comprises an optical filter, wherein the optical filter is arranged between the Y-shaped optical fiber and the optical fiber spectrometer, and the Y-shaped optical fiber is connected with the optical fiber spectrometer through the optical filter.

The second purpose of the invention can be achieved by adopting the following technical scheme:

A construction method of the molecularly imprinted fluorescent optical fiber sensor comprises the following steps:

Synthesizing molecularly imprinted polymer nano-microspheres;

dispersing a part of synthesized molecularly imprinted polymer nano-microspheres in water to prepare molecularly imprinted microsphere aqueous dispersion;

Transferring part of the prepared dispersion liquid into a small conical bottle, adding polyethylene glycol methyl diacrylate and 2-hydroxy-2-methyl propiophenone, magnetically stirring for a period of time, and degassing to obtain a semitransparent gel film pre-polymerization liquid;

Inserting the quartz optical fiber into a hollow glass tube, injecting a part of gel film pre-polymerization liquid into the bottom end of the hollow glass tube, carrying out photopolymerization under an ultraviolet lamp for a period of time, and taking out the quartz optical fiber to obtain the quartz optical fiber for modifying the gel film containing the molecularly imprinted microspheres;

The laser light source, the Y-shaped optical fiber and the optical fiber spectrometer are sequentially connected, and the quartz optical fiber for modifying the gel film containing the molecular imprinting microsphere is connected with the Y-shaped optical fiber through the flange adapter.

Further, the synthetic molecularly imprinted polymer nanosphere specifically comprises:

Filling template molecule powder into a round-bottom flask, adding acetonitrile solution to perform ultrasonic full dissolution, adding methacrylic acid, divinylbenzene and azobisisobutyronitrile, performing ultrasonic full dissolution, introducing nitrogen for a period of time, and sealing the round-bottom flask by using an adhesive tape;

Putting the round-bottom flask into a constant-temperature water bath for reaction to obtain a white precipitation polymer, namely the molecularly imprinted polymer nano-microsphere;

Centrifuging to remove the solvent in the round-bottom flask, washing to remove the unreacted organic solvent, and eluting the template molecules on the molecularly imprinted polymer nanospheres;

Putting the molecular imprinting polymer nano-microspheres in a vacuum drying oven overnight to obtain the substitute molecular imprinting polymer.

Further, the washing step is to remove the unreacted organic solvent and elute the template molecule on the molecularly imprinted polymer nanosphere, and specifically includes:

Repeatedly washing with a mixed solution of methanol and water to remove unreacted organic solvent;

Eluting the template molecules on the molecularly imprinted polymer nano-microspheres on a shaking table by using a mixed elution solution of methanol and acetic acid until the template molecules of the supernatant of the eluent cannot be detected on an ultraviolet spectrophotometer, and washing away the acetic acid by using methanol.

further, in the mixed solution of methanol and water, the ratio of methanol: water 1: 1.

further, in the elution solution of methanol and acetic acid, the ratio of methanol: ethanol ═ 8: 2.

Further, the template molecule powder is filled into a round-bottom flask, specifically: 41mg to 42mg of template molecule powder is weighed and charged into a round bottom flask.

Further, the adding of methacrylic acid, divinylbenzene and azobisisobutyronitrile specifically comprises: adding 85-87 mul of methacrylic acid, 371-372 mul of divinylbenzene and 14-15 mg of azobisisobutyronitrile.

further, the partially synthesized molecularly imprinted polymer nanospheres are specifically: weighing 2-3 mg of molecularly imprinted polymer nano-microspheres.

further, the moving part is used for moving the prepared dispersion liquid into a small conical bottle, and specifically comprises the following steps: 2-4 ml of the prepared dispersion is transferred into a small conical bottle.

Further, the adding of the polyethylene glycol methyl diacrylate and the 2-hydroxy-2-methyl propiophenone specifically comprises the following steps: adding 1.6-20 ml of polyethylene glycol methyl diacrylate with average molecular weight of 700 and 22-24 mul of 2-hydroxy-2-methyl propiophenone.

Further, the insertion of the silica fiber into the hollow glass tube specifically comprises:

And sleeving the quartz optical fiber into a conical plastic mold, and inserting the conical plastic mold into the hollow glass tube to fix the quartz optical fiber in the center of the hollow glass tube.

Further, after injecting a part of gel film pre-polymerization liquid into the bottom end of the hollow glass tube, adjusting the distance between the quartz optical fiber and the bottom end of the hollow glass tube to be 0.2-0.3 cm.

Further, injecting a part of gel film pre-polymerization liquid into the bottom end of the hollow glass tube specifically comprises: and injecting 18-22 mul of the gel film pre-polymerization solution prepared in the second step into the bottom end 10 of the hollow glass tube.

The third purpose of the invention can be achieved by adopting the following technical scheme:

A fluorescence detection method based on the molecularly imprinted fluorescent optical fiber sensor comprises the following steps:

Absorbing the detection solution into a centrifugal tube, putting the quartz optical fiber into the centrifugal tube for soaking, and performing ultrasonic absorption for a period of time;

After adsorption is finished, taking out the quartz optical fiber, soaking the quartz optical fiber in deionized water, and washing away unadsorbed residual adsorption liquid;

the processed quartz optical fiber is connected into the whole instrument through the flange adapter, laser emitted by the laser source is transmitted to the gel film on the quartz optical fiber through the Y-shaped optical fiber, a fluorescence signal of the gel film is reflected back to the Y-shaped optical fiber and is transmitted to the optical fiber spectrometer through the Y-shaped optical fiber, and therefore fluorescence detection is achieved.

further, absorb detection solution in the centrifuging tube, specifically be: sucking 0.8 ml-1.2 ml of detection solution into a centrifuge tube.

Compared with the prior art, the invention has the following beneficial effects:

1. The sensor combines the molecular imprinting technology with the optical fiber sensing technology, not only has the advantages of high selectivity of the molecular imprinting polymer, miniaturization of the optical fiber sensing technology and the like, but also has the advantages of lightness, rapidness, simple and convenient operation, low cost and the like compared with a large-scale optical sensor; different from the existing optical fiber sensor, the molecular imprinting material coated in the design can be quickly washed away by changing the conditions after the detection is finished, namely, the modified optical fiber probe can be recycled, so that the material cost is low; the instrument has the advantages of being detachable and replaceable while keeping the light transmission efficiency, can realize rapid on-site monitoring of multiple targets, has certain research significance for on-site rapid detection of antibiotics in the environmental water body, can be applied to on-site rapid monitoring of the antibiotics in the environmental water body, and solves the problems that the existing antibiotic on-site monitoring method is poor in stability and reproducibility, high in analysis cost and difficult to provide real-time pollution data of the antibiotics in the environmental water body.

2. The sensor can be provided with the optical filter between the Y-shaped optical fiber and the optical fiber spectrometer, the Y-shaped optical fiber is connected with the optical fiber spectrometer through the optical filter, and the exciting light which is reflected excessively can be filtered through the optical filter so as to reduce the detection error.

3. in the modification process of the optical fiber probe, polyethylene glycol methyl diacrylate is added when gel film pre-polymerization liquid is prepared, the polyethylene glycol methyl diacrylate can initiate free radical polymerization by a photoinitiator under illumination to form a net structure, and the molecularly imprinted microspheres are wrapped in the gel film to keep the fluorescence efficiency.

4. In the modification process of the optical fiber probe, the quartz optical fiber is sleeved into the conical plastic mold, and the conical plastic mold is inserted into the hollow glass tube, so that the quartz optical fiber is fixed at the center of the hollow glass tube, and the detection error is reduced; and after injecting gel film pre-polymerization liquid, adjusting the distance between the quartz optical fiber and the bottom end of the hollow glass tube to be 0.2-0.3 cm so as to reduce the detection error among different components.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.

FIG. 1 is a structural diagram of a molecularly imprinted fluorescent optical fiber sensor according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of a gel film modified by a fiber-optic probe according to an embodiment of the present invention.

FIG. 3 is a schematic diagram of a silica optical fiber for synthesizing a modified gel film according to an embodiment of the present invention.

FIG. 4 is a diagram illustrating the effect of testing errors before and after adsorption.

FIG. 5 is a graph showing the enhancement of the fluorescence effect of adsorption test according to the embodiment of the present invention.

FIG. 6 is a time chart of the optimized adsorption effect according to the embodiment of the present invention.

FIG. 7 is a graph showing the effect of selectivity on adsorbed species in accordance with an embodiment of the present invention.

the system comprises a laser light source 1, a 2-Y-shaped optical fiber, a 3-quartz optical fiber, a 4-flange adapter, a 5-optical fiber spectrometer, a 6-dark box, a 7-computer, an 8-optical filter, a 9-conical plastic mold, a 10-hollow glass tube and an 11-ultraviolet lamp.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer and more complete, the technical solutions in the embodiments of the present invention will be described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some embodiments of the present invention, but not all embodiments, and all other embodiments obtained by a person of ordinary skill in the art without creative efforts based on the embodiments of the present invention belong to the protection scope of the present invention.