A fiber-integrated rare earth ion-doped nanoparticle water molecule sensor and its application

Abstract

The present invention discloses a fiber-integrated rare earth ion-doped nanoparticle water molecule sensor and its application. The fiber-integrated rare earth ion-doped nanoparticle water molecule sensor comprises a chemical formula of NaLuF4:Yb 3+ / X 3+ / Gd 3+ Rare earth ion-doped nanoparticles and fibers integrating rare earth ion-doped nanoparticles, wherein X 3+ Refers to rare earth ions; pump light is irradiated on the fiber to cause the rare earth ion-doped nanoparticles to achieve upconversion luminescence, and then water molecules are sensed by measuring the upconversion luminescence spectrum, with good measurement sensitivity and linearity; and the integrated device of the upconversion luminescent nanoparticles and fiber structure of the present invention has high integration, good portability, and is easy to excite and detect the spectrum. It also has the advantages of high photostability, no autofluorescence background, low toxicity and real-time detection, and can be used in environmental humidity monitoring, cell biology, pharmacology, environmental health and safety, fine chemical industry and precision agriculture.

Description

Technical Field

[0001] The invention relates to the technical fields of up-conversion luminescent materials, sensors and nanophotonics, and in particular to a fiber-integrated rare earth ion-doped nanoparticle water molecule sensor and its application. Background Art

[0002] Water molecule sensing has important applications in many scientific research and industrial production fields. Among water molecule sensing optical probes, upconversion luminescent nanoparticle probes have the advantages of high photostability, no autofluorescence background and low toxicity, which have attracted widespread research interest. For upconversion luminescent nanoparticle water detection, when excited by a pump laser, the luminescence peak intensity of the doped rare earth ions varies with the content of water molecules, and is thus used to characterize the water molecule content.

[0003] In the past studies, Er 3+ In 2016, Shaohong Guo et al. from Nanjing University of Technology used a ligand-free NaYF4:Yb 3+ / Er 3+ Nanoparticle water probes, using the nonlinear upconversion of rare earth ion-doped nanoparticles, have demonstrated a simple method for sensing water molecules, with a detection limit of 80 ppm for water molecules in N,N-dimethylformamide solvent (ACS Applied Materials & Interfaces, 8, 847, 2016). In 2017, Daqi Chen et al. from Hangzhou Dianzi University synthesized a core-shell structured NaGdF4:20% Yb 3+ / 1%Er 3+ @NaYF4:20%Yb 3+ / 10%Nd 3+ Upconversion nanoparticles, including Nd 3+ Ion is a sensitizer, Er 3+ As an activator, the sensitivity in N,N-dimethylformamide solvent is 1.60% / vol% (Journal of Materials Chemistry C, 5, 5434-5443, 2017). In 2020, Zaifa Pan et al. from Zhejiang University of Technology synthesized a hollow NaBiF4:Yb by a one-step solvothermal method without surface modification. 3+ / Er 3+Upconversion nanoparticles can be used as optical probes for the determination of water molecules in organic solvents, with a sensitivity of 1.879% / vol% in ethanol solvent and 1.074% / vol% in acetone solvent. In 2020, Ling Zhang et al. from Jilin University used a strong red upconversion luminescent LiErF4 nanosystem, namely LiErF4@LiYF4 and its related derivatives LiErF4:0.5%Tm 3+ @LiYF4, among them 3+ The ions act as both activators and sensitizers and can be used for real-time and long-term water monitoring, with a sensitivity of 1.522% / vol% in acetonitrile solvent and 3.067% / vol% in dimethyl sulfoxide solvent (Nano Research, 13, 2803, 2020). However, the sensitivity of the upconversion luminescent nanoparticle water molecule probes currently developed is still limited.

[0004] Therefore, the prior art still needs to be improved and developed. Summary of the invention

[0005] In view of the above-mentioned deficiencies in the prior art, the object of the present invention is to provide a fiber-integrated rare earth ion-doped nanoparticle water molecule sensor and its application, aiming to solve the problem of low sensitivity of the existing upconversion luminescent nanoparticle water molecule probe.

[0006] The technical solution of the present invention is as follows:

[0007] A fiber-integrated rare earth ion-doped nanoparticle water molecule sensor, comprising rare earth ion-doped nanoparticles and fibers integrating the rare earth ion-doped nanoparticles, wherein the chemical formula of the rare earth ion-doped nanoparticles is NaLuF4:Yb 3+ / X 3+ / Gd 3+ , where X 3+ Refers to rare earth ions.

[0008] The fiber-integrated rare earth ion-doped nanoparticle water molecule sensor, wherein the NaLuF4:Yb 3+ / X 3+ / Gd 3+ X in 3+ Selected from Er 3+ 、Tm 3+ 、Ho 3+ At least one of .

[0009] The fiber-integrated rare earth ion-doped nanoparticle water molecule sensor, wherein the rare earth ion-doped nanoparticles are attached to the surface of the fiber or embedded in the interior of the fiber.

[0010] The fiber-integrated rare earth ion-doped nanoparticle water molecule sensor, wherein the rare earth ion-doped nanoparticles are of a hexagonal phase structure.

[0011] The fiber-integrated rare earth ion-doped nanoparticle water molecule sensor, wherein the rare earth ion-doped nanoparticles are cylindrical.

[0012] The fiber-integrated rare earth ion-doped nanoparticle water molecule sensor, wherein the axial dimension of the cylindrical rare earth ion-doped nanoparticles is in the order of hundreds of nanometers, and the radial dimension is in the order of tens of nanometers.

[0013] The fiber-integrated rare earth ion-doped nanoparticle water molecule sensor, wherein the fiber is selected from one of glass optical fiber, quartz optical fiber, plastic optical fiber, silk, and spider silk.

[0014] The fiber-integrated rare earth ion-doped nanoparticle water molecule sensor, wherein the rare earth ion-doped nanoparticles are attached to the surface of the glass optical fiber.

[0015] An application of the fiber-integrated rare earth ion-doped nanoparticle water molecule sensor is used in environmental humidity monitoring, cell biology, and pharmacology.

[0016] Beneficial effect: The present invention provides a fiber-integrated rare earth ion-doped nanoparticle water molecule sensor and its application, wherein the fiber-integrated rare earth ion-doped nanoparticle water molecule sensor comprises a chemical formula of NaLuF4:Yb 3+ / X 3+ / Gd 3+ Rare earth ion-doped nanoparticles and fibers integrating the rare earth ion-doped nanoparticles; wherein X 3+ Refers to rare earth ions; rare earth ion-doped nanoparticle water molecule probes improve the sensitivity of water molecule detection; pump light is irradiated on the fiber to cause the rare earth ion-doped nanoparticles to achieve upconversion luminescence, and then water molecule sensing is performed by measuring the upconversion luminescence spectrum, with good measurement sensitivity and linearity; and the integrated device of the upconversion luminescent nanoparticles and fiber structure of the present invention has high integration, good portability, and is easy to excite and detect the spectrum. It also has the advantages of high photostability, no autofluorescence background, low toxicity and real-time detection, and can be used in many fields such as environmental humidity monitoring, cell biology, pharmacy, environmental health and safety, fine chemical industry and precision agriculture. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The NaLuF4:40%Yb integrated microstructured glass optical fiber of Example 1 of the present invention 3+ / 1%Tm 3+ / 45%Gd3+ Schematic diagram of the cross section of rare earth ion doped upconversion luminescent nanoparticle water molecule sensor;

[0018] Figure 2 The NaLuF4:40%Yb integrated microstructured glass optical fiber of Example 1 of the present invention 3+ / 1%Tm 3+ / 45%Gd 3+ Scanning electron microscope image of rare earth ion doped upconversion luminescent nanoparticle water molecule sensor;

[0019] Figure 3 The NaLuF4:40%Yb of Example 1 of the present invention 3+ / 1%Tm 3+ / 45%Gd 3+ Upconversion luminescence spectrum of microstructured glass optical fiber coated with rare earth ion doped upconversion luminescent nanoparticles;

[0020] Figure 4 The NaLuF4:40%Yb of Example 1 of the present invention 3+ / 1%Tm 3+ / 45%Gd 3+ The integrated emission light intensity of the microstructured glass optical fiber coated with rare earth ion doped upconversion luminescent nanoparticles changes with the relative humidity of the environment, where a is the light with a wavelength of 475nm, b is the integrated light, and c is the light with a wavelength of 450nm;

[0021] Figure 5 The NaLuF4:40%Yb embedded in degummed silk in Example 2 of the present invention 3+ / 1%Tm 3+ / 45%Gd 3+ Scanning electron microscope image of rare earth ion doped upconversion luminescent nanoparticles;

[0022] Figure 6 This is the upconversion luminescence spectrum of the rare earth ion-doped upconversion luminescent nanoparticles embedded in degummed silk in wet and dry environments according to Example 2 of the present invention. DETAILED DESCRIPTION

[0023] The present invention provides a fiber-integrated rare earth ion-doped nanoparticle water molecule sensor and its application. To make the purpose, technical solution and effect of the present invention clearer and more specific, the present invention is further described in detail below. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0024] In the embodiments and the scope of the patent application, unless the text specifically defines the article, "a", "an", "the" and "the" may also include plural forms. If there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features.

[0025] It should be further understood that the wording "comprising" used in the specification of the present invention refers to the presence of the features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or their groups. The wording "and / or" used herein includes all or any unit and all combinations of one or more associated listed items.

[0026] It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as generally understood by those skilled in the art in the art to which the present invention belongs. It should also be understood that terms such as those defined in general dictionaries should be understood to have meanings consistent with the meanings in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless specifically defined as herein.

[0027] There are few patents for upconversion luminescent nanoparticle water molecule probes, and they are mainly based on biochemical molecular sensing. In 2015, patent 201510067146.2, Wang Shuo and others from Tianjin University of Science and Technology designed a sensing material based on upconversion nanoparticles and its preparation method, combining the strong fluorescence of upconversion nanoparticles with the specific recognition of molecular imprinting polymers to identify cytochrome C. In 2015, patent 201510822458.X, Wang Junping and others from Tianjin University of Science and Technology used SiO2 film-coated upconversion luminescent nanoparticles as carriers to synthesize a Salmonella upconversion nanofluorescent sensing material that has a strong recognition function for Salmonella. In 2021, patent 202011468438.4, Liu Danqing and others from Harbin University of Science and Technology synthesized NaBiF4:Yb at room temperature and mild conditions. 3+ / Er 3+ Upconversion nanoparticles are used for ECL detection of pathogenic bacteria (Escherichia coli O157:H7). In 2021, patent 202111336520.6, Lu Geyu et al. of Jilin University used a spin spray method to convert LiErF4:0.5% Tm 3+@LiYF4 upconversion nanoparticles are combined with PMMA photonic crystals, and the coupling effect between the photonic crystal band gap and the excitation light field is used to enhance the excitation light field, making LiErF4:0.5% Tm 3+ @LiYF4 The luminescence intensity of upconversion nanoparticles was significantly improved, and a non-contact cholesterol fluorescence sensor was constructed. In 2022, patent 202210371671.3, Yang Liang and others from the Hefei Institutes of Physical Science, Chinese Academy of Sciences designed a method for preparing a core-shell structure upconversion nanoparticle fluorescence sensing probe, which can realize the visual instant detection of mesna.

[0028] However, these technologies are all fluorescent probes for the detection of biochemical molecules, not water molecules. 3+ The upconversion luminescent nanoparticle water molecule probe with ions as the luminescent center has low sensitivity.

[0029] Therefore, further research is needed on water molecule sensors with high photostability, short response time, no autofluorescence background, and low toxicity.

[0030] Based on this, the present invention provides a fiber-integrated rare earth ion-doped nanoparticle water molecule sensor, comprising rare earth ion-doped nanoparticles and fibers integrating the rare earth ion-doped nanoparticles, wherein the chemical formula of the rare earth ion-doped nanoparticles is NaLuF4:Yb 3+ / X 3+ / Gd 3+ , where X 3+ Refers to rare earth ions.

[0031] In this embodiment, by using the chemical formula of NaLuF4:Yb 3+ / X 3+ / Gd 3+ Rare earth ion doped nanoparticles are integrated on the fiber, and then pump light is irradiated on the fiber to cause the rare earth ion doped nanoparticles to achieve upconversion luminescence, and water molecule sensing is performed by measuring the upconversion luminescence spectrum. The fiber-integrated rare earth ion doped nanoparticle water molecule sensor has good measurement sensitivity and linearity, and the device has high device integration, good portability, and is easy to excite and detect the spectrum.

[0032] The fiber-integrated rare earth ion-doped nanoparticle water molecule sensor of this embodiment has the following advantages:

[0033] (1) The existing Karl Fischer coulometric titration method has been widely used as a water detection method, but it usually has the disadvantages of using toxic chemical reagents and time-consuming measurements, which hinders its application in environmental detection; compared with it, the present invention has the advantages of high photostability, no autofluorescence background, low toxicity and real-time detection.

[0034] (2) Compared with the existing upconversion luminescent nanoparticle water molecule probe, the rare earth ion doped upconversion luminescent nanoparticle water molecule sensor of the present invention improves the sensitivity of water molecule detection.

[0035] (3) Compared with the existing rare earth ion doped upconversion luminescent nanoparticle water molecule probe, the present invention relates to an integrated device of upconversion luminescent nanoparticles and fiber structures, which has good portability, is easy to excite and detect the spectrum, and can be used in many fields such as environmental humidity detection, cell biology, pharmacology, environmental health and safety, fine chemical industry and precision agriculture.

[0036] In some embodiments, the NaLuF4:Yb 3+ / X 3+ / Gd 3+ X in 3+ Selected from Er 3+ 、Tm 3+ 、Ho 3+ At least one of the following. 3+ 、Tm 3+ 、Ho 3+ As a doping element, it can effectively improve the sensitivity of water molecule sensors.

[0037] In some embodiments, the rare earth ion-doped nanoparticles are attached to the surface of the fiber or embedded in the interior of the fiber; when the pump light is irradiated on the fiber, the rare earth ion-doped nanoparticles can achieve up-conversion luminescence, and then water molecule sensing is performed by measuring the up-conversion luminescence spectrum, with good measurement sensitivity and linearity.

[0038] In some embodiments, the fiber is selected from one of glass optical fiber, quartz optical fiber, plastic optical fiber, silk, and spider silk; glass optical fiber, quartz optical fiber, plastic optical fiber, silk, and spider silk are selected as the attachment area of ​​rare earth ion-doped nanoparticles, and the fiber and nanoparticles are combined to form an integrated device, forming a convenient sensor, thereby simplifying the spectral excitation and detection system; when the pump light is irradiated on the fiber, the rare earth ion-doped nanoparticles attached to the fiber surface or embedded in the fiber perform up-conversion luminescence, and then by measuring the up-conversion luminescence spectrum, the spectral line intensity and the water molecule content are in linear inverse proportion, thereby performing water molecule sensing.

[0039] In a specific embodiment, the rare earth ion-doped nanoparticles are attached to the surface of the glass optical fiber.

[0040] In some embodiments, the rare earth ion-doped nanoparticles have a hexagonal phase structure.

[0041] In some embodiments, the rare earth ion-doped nanoparticles are cylindrical.

[0042] In some embodiments, the axial dimension of the cylindrical rare earth ion-doped nanoparticles is hundreds of nanometers and the radial dimension is tens of nanometers. Under this dimension, the water molecule sensor has good measurement sensitivity and linearity.

[0043] In addition, the present invention also provides an application of a fiber-integrated rare earth ion-doped nanoparticle water molecule sensor, wherein the fiber-integrated rare earth ion-doped nanoparticle water molecule sensor is used for environmental humidity monitoring, cell biology, pharmacology, environmental health and safety, fine chemical industry, precision agriculture, etc.

[0044] The following further examples are given to illustrate the present invention in detail. It should also be understood that the following examples are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the above content of the present invention belong to the scope of protection of the present invention.

[0045] Example 1

[0046] like Figure 1 Shown is a microstructured glass fiber integrated NaLuF4:40% Yb 3+ / 1%Tm 3+ / 45%Gd 3+ Schematic diagram of the cross section of the rare earth ion doped upconversion luminescent nanoparticle water molecule sensor. NaLuF4:40%Yb 3+ / 1%Tm 3+ / 45%Gd 3+ The anhydrous ethanol solution of rare earth ion doped upconversion luminescent nanoparticles is dropped on the surface of a microstructured glass optical fiber with a radius of 12 microns; that is, the surface of the glass optical fiber 1 is attached with NaLuF4:40%Yb 3+ / 1%Tm 3+ / 45%Gd 3+ Rare earth ion doped upconversion luminescent nanoparticle layer 2, wherein the reference numeral 21 is NaLuF4:40% Yb with a thickness of 160 nm 3+ / 1%Tm 3+ / 45%Gd 3+ Rare earth ion doped upconversion luminescent nanoparticle layer, reference numeral 22 is NaLuF4:40% Yb with a thickness of 80 nm 3+ / 1%Tm 3+ / 45%Gd 3+ Rare earth ion doped upconversion luminescent nanoparticle layer.

[0047] like Figure 2As shown in the scanning electron microscope image, the thickness of the rare earth ion doped upconversion luminescent nanoparticles deposited on the upper surface of the microstructured glass optical fiber is 160nm, the attachment area is 72°, and the thickness of the rare earth ion doped upconversion luminescent nanoparticles deposited on the remaining surfaces of the microstructured glass optical fiber is 80nm.

[0048] like Figure 3 As shown in the figure, the 980nm wavelength pump laser is incident from the end face of the microstructured glass fiber and excites NaLuF4:40%Yb through evanescent field coupling. 3+ / 1%Tm 3+ / 45%Gd 3+ Tm of rare earth ion doped upconversion luminescent nanoparticles 3+ The ions undergo upconversion luminescence.

[0049] like Figure 4 As shown, the characterization of environmental relative humidity: As the relative humidity of the environment increases, the integrated emission light intensity, the luminous intensity at 450nm and 475nm wavelengths decrease. When the integrated emission light intensity, the luminous intensity at 450nm wavelength and the luminous intensity at 475nm wavelength are selected as indicators, the detection sensitivity in the linear region is 1.849% / RH%, 1.865% / RH% and 2.104% / RH%, respectively, where RH% is relative humidity.

[0050] Example 2

[0051] The embedded NaLuF4:40%Yb 3+ / 1%Tm 3+ / 45%Gd 3+ Rare earth ion doped upconversion luminescent nanoparticle silk fibers.

[0052] Raise three-instar silkworms and feed them mulberry leaves twice in the first week. After that, feed them with mulberry leaves coated with NaLuF4:40%Yb twice a day. 3+ / 1%Tm 3+ / 45%Gd 3+ Silkworms were fed with mulberry leaves doped with rare earth ion upconversion luminescent nanoparticles until all silkworms began to spin silk. The cocoons were harvested 7 days after the silkworms spun silk. Then, the resulting silk was degummed before testing. The harvested cocoons were dried in a drying oven at 110°C for 60 minutes and 80°C for 180 minutes, and then dried in air at room temperature for 24 hours. Subsequently, the resulting silk was immersed in a boiling Na2CO3 aqueous solution (0.5wt%) for 30 minutes and washed three times with deionized water to thoroughly desorb the sericin. Finally, it was dried at 60°C in a drying oven for 12 hours to obtain NaLuF4:40%Yb 3+ / 1%Tm 3+ / 45%Gd 3+ UCNPs embedded in silk fibers.

[0053] like Figure 5 As shown, it is embedded NaLuF4:40%Yb 3+ / 1%Tm 3+ / 45%Gd 3+ Scanning electron microscope image of silk fiber doped with rare earth ion upconversion luminescent nanoparticles, which shows that rare earth ion doping with upconversion luminescent nanoparticles does not destroy the fiber structure of silk. Figure 6 Shown are embedded NaLuF4:40%Yb in wet and dry environments 3+ / 1%Tm 3+ / 45%Gd 3+ Upconversion luminescence spectrum of silk doped with rare earth ion upconversion luminescent nanoparticles. 3+ Compared with the characteristic emission peak intensity of ions, Tm 3+ The characteristic emission peak intensity of ions decreased, indicating that the fiber-integrated NaLuF4:40%Yb 3+ / 1%Tm 3+ / 45%Gd 3+ Rare earth ion doped upconversion luminescent nanoparticles have the potential for environmental humidity detection.

[0054] In summary, the present invention provides a fiber-integrated rare earth ion-doped nanoparticle water molecule sensor and its application. The fiber-integrated rare earth ion-doped nanoparticle water molecule sensor comprises a chemical formula of NaLuF4:Yb 3+ / X 3+ / Gd 3+ Rare earth ion-doped nanoparticles and fibers integrating the rare earth ion-doped nanoparticles; 3+ 、Tm 3+ 、Ho 3+ The doped nanoparticle water molecule sensor improves the sensitivity of water molecule detection; pump light is used to irradiate the fiber to cause the rare earth ion-doped nanoparticles to achieve upconversion luminescence, and then water molecule sensing is performed by measuring the upconversion luminescence spectrum, with good measurement sensitivity and linearity; and the integrated device of the upconversion luminescent nanoparticles and fiber structure of the present invention has high integration, good portability, and is easy to excite and detect the spectrum, and at the same time has the advantages of high photostability, no autofluorescence background, low toxicity and real-time detection, and can be used in many fields such as environmental humidity monitoring, cell biology, pharmacy, environmental health and safety, fine chemical industry and precision agriculture.

[0055] It should be understood that the application of the present invention is not limited to the above examples. For ordinary technicians in this field, improvements or changes can be made based on the above description. All these improvements and changes should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A fiber-integrated rare earth ion-doped nanoparticle water molecule sensor, characterized in that: The invention comprises rare earth ion doped nanoparticles and fibers integrated with the rare earth ion doped nanoparticles, wherein the chemical formula of the rare earth ion doped nanoparticles is NaLuF4:Yb 3+ / Tm 3+ / Gd 3+ ; The rare earth ion doped nanoparticles are attached to the surface of the fiber or embedded in the inside of the fiber; the rare earth ion doped nanoparticles are of hexagonal phase structure; the rare earth ion doped nanoparticles are cylindrical; the axial size of the cylindrical rare earth ion doped nanoparticles is hundreds of nanometers and the radial size is tens of nanometers; the fiber is selected from one of glass optical fiber, quartz optical fiber, plastic optical fiber, silk and spider silk; The fiber-integrated rare earth ion-doped nanoparticle water molecule sensor is used in environmental humidity monitoring, cell biology, and pharmacology.

2. The fiber-integrated rare earth ion-doped nanoparticle water molecule sensor according to claim 1, characterized in that: The rare earth ion-doped nanoparticles are attached to the surface of the glass optical fiber.

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