Preparation method of terbium organic composite nanoprobe for fluoride ion detection in aqueous solution

Abstract

This invention discloses a method for preparing a terbium-organic composite nanoprobe for fluoride ion detection in aqueous solution, comprising using a crown-shaped terbium-gallium dication complex as a detection signal source; and mixing the crown-shaped terbium-gallium dication complex with block copolymer F127 to self-assemble and prepare the terbium-organic composite nanoprobe. The specific preparation method includes the following steps: S1, terbium ions, gallium ions, salicylhydroxyxamic acid, and sodium benzoate are mixed and coordinated in methanol to prepare a crown-shaped terbium-gallium dication complex. S2, the methanol solution of the crown-shaped terbium-gallium dication complex obtained in step S1 is mixed with the block copolymer F127 and stirred at room temperature to obtain a clear and transparent mixed solution. S3, the mixed solution from step S2 is injected into deionized water, resulting in a rapid nano-self-assembly reaction to obtain the terbium-organic composite luminescent nanoprobe. The terbium-organic composite luminescent nanomaterial obtained by this invention has uniform size, high luminescence intensity, and no aggregation or precipitation phenomena, enabling rapid detection of fluoride ions in aqueous solution with a response range of 0.19 ppm to 18.81 ppm.

Description

Technical Field

[0001] This invention belongs to the field of aqueous solution fluoride ion detection technology, and specifically relates to a method for preparing a terbium organic composite nanoprobe for aqueous solution fluoride ion detection. Background Technology

[0002] A normal adult's body contains approximately 2.6g of fluoride, and the human body ingests small amounts of fluoride daily through diet and drinking water. However, a daily intake exceeding 4mg can cause poisoning, and excessive fluoride ions are a significant factor contributing to neurotoxicity. Therefore, developing a technology for the rapid detection of fluoride ions in aqueous solutions is currently in urgent need.

[0003] Rare-earth terbium ions possess excellent optical characteristics such as narrow half-width at half-maximum (FWHM), long lifetime, and strong resistance to bleaching, making them potentially valuable for applications in biosensor imaging, solar energy conversion, lighting displays, and communications. However, terbium ions exhibit weak luminescence signals due to their weak Rabotic law extinction ability and low fluorescence quantum efficiency.

[0004] Therefore, this invention utilizes the self-assembly of block copolymers to prepare terbium organic composite nanoprobes, thereby improving the intensity of terbium ion luminescence signal and environmental stability. When used as a fluorescent probe for the detection of fluoride ions in aqueous solutions, it features high reliability, low cost, and high sensitivity. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing a terbium organic composite nanoprobe for detecting fluoride ions in aqueous solutions, which can solve one or more of the above-mentioned technical problems.

[0006] To achieve the above objectives, the technical solution proposed by this invention is as follows:

[0007] The method for preparing terbium organic composite nanoprobes for fluoride ion detection in aqueous solutions is characterized by the following steps: using a crown-shaped terbium-gallium biscation complex as a detection signal source, the crown-shaped terbium-gallium biscation complex is mixed with block copolymer F127 (poloxam) to prepare terbium organic composite nanoprobes through self-assembly, and the composite nanoprobes are obtained by a rapid nanoprecipitation method using block copolymers.

[0008] A method for preparing a terbium organic composite nanoprobe for detecting fluoride ions in aqueous solution, characterized by comprising the following steps:

[0009] S1 Preparation of a methanol solution of crown terbium gallium dication complex: terbium nitrate pentahydrate, salicylhydroxyxamic acid, gallium nitrate hydrate, sodium benzoate, methanol and pyridine are mixed in a molar ratio of 0.25:1:1:3:980:25, stirred for 12 hours, filtered to remove white powder, and the filtrate is sealed and stored for later use.

[0010] S2. The filtrate from step S1 is mixed with block copolymer F127 at a volume ratio of 0.2 to 4:1 and stirred for 6 to 24 hours.

[0011] S3. Slowly inject the mixed solution from step S2 into deionized water, with a volume ratio of 1:10 to 20 between the mixed solution and the deionized water.

[0012] S4 After step S3, a self-assembly promoter is added at 3-10% of the total volume to obtain a terbium organic composite nanoprobe for detecting fluoride ions in aqueous solution.

[0013] Preferably, the self-assembly promoter in step (4) is a solvent with non-polar characteristics, including: oleic acid, oleylamine, tri-n-octylphosphine, tri-n-octylphosphine oxide, cyclohexane, n-hexane, and petroleum ether.

[0014] The technical effects of this invention are:

[0015] The terbium-organic composite nanoprobe solid or aqueous dispersion for fluoride ion detection in aqueous solution of this invention produces emission peaks with center wavelengths of 489–492, 544–547, 584–587, and 620–623 nm under ultraviolet light excitation at 250–400 nm. Adding different concentrations of fluoride ions to the aqueous dispersion of the terbium-organic composite nanoprobe results in varying degrees of change in the emission intensity signal. This probe features high reliability, low cost, and high sensitivity. Attached Figure Description

[0016] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0017] In the attached diagram:

[0018] Figure 1 Transmission electron microscope image of terbium-organic composite nanoprobe;

[0019] Figure 2 :Tb 3+ Ga 3+ X-ray diffraction pattern of a crown-shaped terbium-gallium dication complex composed of salicylic acid, hydroxamic acid, and benzoic acid;

[0020] Figure 3 Fluorescence emission spectrum of terbium organic composite nanoprobe dispersion at room temperature, with deionized water as solvent;

[0021] Figure 4 :Tb 3+ Ga 3+ A photograph of the luminescence of a crown-shaped terbium-gallium dication complex composed of salicylic acid, hydroxamic acid, and benzoic acid under a 360 nm UV lamp;

[0022] Figure 5 Fluorescence emission spectra of rare earth organic composite nanoprobe dispersions with different concentrations of fluoride ions added;

[0023] Figure 6 The relationship between fluoride ion concentration and the luminescence intensity of rare earth organic composite nanoprobes, where x is the negative ion concentration and y is the luminescence intensity. Detailed Implementation

[0024] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. The illustrative embodiments and descriptions are only used to explain the present invention and are not intended to unduly limit the present invention.

[0025] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0026] A method for preparing a terbium-organic composite nanoprobe for fluoride ion detection in aqueous solution includes the following steps: using a crown-shaped terbium-gallium dication complex as the detection signal source, the crown-shaped terbium-gallium dication complex is mixed with block copolymer F127 and self-assembled to prepare the terbium-organic composite nanoprobe; the composite nanoprobe is obtained using a rapid nanoprecipitation method with block copolymers. Adding different concentrations of fluoride ions to the aqueous dispersion of the terbium-organic composite nanoprobe results in varying degrees of change in the luminescence intensity signal.

[0027] The specific steps are as follows:

[0028] S1 Preparation of a methanol solution of a crown-shaped terbium-gallium dication complex: Terbium nitrate pentahydrate, salicylic acid hydroxamic acid, gallium nitrate hydrate, sodium benzoate, methanol, and pyridine were mixed in a molar ratio of 0.25:1:1:3:980:25 and stirred for 12 hours.

[0029] Filter to remove the white powder, and seal the filtrate for later use.

[0030] Specifically: Salicylic acid (0.1531 g, 1.0 mmol), Tb(NO3)3·5H2O (0.25 mmol, 435.02 g / mol),

[0031] 0.10876 g), Ga(NO3)3·xH2O (0.2557 g, 1.0 mmol) were dissolved in 40 mL of methanol, and sodium benzoate (0.4323 g, 0.10876 g, 0.2557 g, 1.0 mmol) was added.

[0032] Add 3 mmol), stir overnight, add 2 mL of pyridine, filter to remove white powder, and seal and store the filtrate for later use.

[0033] S2. The filtrate from step S1 is mixed with block copolymer F127 at a volume ratio of 0.2 to 4:1 and stirred for 6 to 24 hours.

[0034] Specifically: Take 2 mL of the filtrate from step S1, add 2 mL of block copolymer F127 while stirring continuously, and stir overnight.

[0035] S3. Slowly inject the mixed solution from step S2 into deionized water, with a volume ratio of 1:10 to 20 between the mixed solution and the deionized water.

[0036] Specifically, the mixed solution from step S2 is slowly injected into 15 mL of deionized water.

[0037] S4 After step S3, a self-assembly promoter is added at 3-10% of the total volume to obtain a terbium organic composite nanoprobe for detecting fluoride ions in aqueous solution.

[0038] Specifically, after step S3, 0.5 mL of a nonpolar solution such as cyclohexane is added to promote self-assembly.

[0039] The terbium-organic composite nanoprobe prepared by the above method, such as Figure 1 Transmission electron microscopy images show that the self-assembled material has nanoprobes with a diameter of 60 nm, assembled from smaller particles.

[0040] like Figure 2 The X-ray diffraction pattern of the crown-shaped terbium-gallium dual-cation complex shows distinct diffraction peaks at 2Theta of 7.5°, 18.8°, 21.3°, and 26.5°, indicating that Tb... 3+ Ga 3+ It has a crystal structure after coordination with salicylic acid and benzoic acid.

[0041] like Figure 3 The fluorescence emission spectrum is obtained under ultraviolet light excitation at a wavelength of 344 nm. The spectrum shows Tb at 491, 546, 585, and 622 nm. 3+ Feature luminescence, corresponding to Tb 3+ Electron transition: 5 D4→ 7 F6 5 D4→ 7 F5 5 D4→ 7 F4 5 D4→ 7 F3.

[0042] like Figure 4 This is a photograph of the emission of a coronal terbium-gallium dual-cation complex under a 360nm ultraviolet lamp. A bright green light can be observed, corresponding to… Figure 3The emission wavelength at 546 nm in the fluorescence spectrum.

[0043] like Figure 5 In aqueous solution, the luminescence intensity of the rare earth organic composite nanoprobe dispersion gradually weakens with increasing fluoride ion concentration, indicating that the probe can be used for the detection of fluoride ion concentration in aqueous solution.

[0044] like Figure 6 The relationship between fluoride ion concentration and the luminescence intensity of rare-earth organic composite nanoprobes is shown. The regression equation for the calibration curve is y = 25925.9 – 11886.8 Log x, with a correlation coefficient R. 2 =0.998.

[0045] This rare-earth organic composite nanoprobe is used in aqueous solutions. The following are specific examples of using this probe to detect fluoride ions in aqueous solutions:

[0046] The prepared rare-earth organic composite nanoprobe was diluted 32 times with deionized water, and the results were measured as follows: Figure 5 The fluorescence spectrum at 0 ppm was obtained. Under the same conditions, fluoride ions were added at concentrations of 0.19 ppm, 0.95 ppm, 3.42 ppm, 8.55 ppm, 11.97 ppm, and 18.81 ppm, and the results were as follows: Figure 5 The fluorescence spectrum was analyzed. The highest emission intensity at a wavelength of 546 nm was recorded, as shown below. Figure 6 As shown, the luminescence intensity has a linear relationship with the Log fluoride ion concentration. The regression equation for the calibration curve is y = 25925.9 – 11886.8Log x, and the correlation coefficient R0 is [value missing]. 2 =0.998.

[0047] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A method for preparing a terbium-organic composite nanoprobe for detecting fluoride ions in aqueous solution, characterized in that: Using a crown-shaped terbium-gallium dication complex as the detection signal source, a terbium organic composite nanoprobe was prepared by self-assembly of the crown-shaped terbium-gallium dication complex and block copolymer F127 via a rapid nanoprecipitation method using block copolymers. The preparation method of the crown-shaped terbium-gallium dication complex included mixing terbium nitrate pentahydrate, salicylic acid hydroxamic acid, gallium nitrate hydrate, sodium benzoate, methanol, and pyridine in a molar ratio of 0.25:1:1:3:980:25, stirring for 12 hours, filtering to remove white powder, and obtaining the filtrate for later use.

2. A method for preparing a terbium organic composite nanoprobe for detecting fluoride ions in aqueous solution, characterized in that, Specifically, the steps include the following: S1 Preparation of a methanol solution of crown terbium gallium dication complex: terbium nitrate pentahydrate, salicylhydroxyxamic acid, gallium nitrate hydrate, sodium benzoate, methanol and pyridine are mixed in a molar ratio of 0.25:1:1:3:980:25, stirred for 12 hours, filtered to remove white powder, and the filtrate is sealed and stored for later use; S2. The filtrate from step S1 is mixed with block copolymer F127 at a volume ratio of 0.2 to 4:1 and stirred for 6 to 24 hours. S3. The mixed solution from step S2 is slowly injected into deionized water at a volume ratio of 1:10 to 20. S4. After step S3, a self-assembly promoter is added at 3 to 10% of the total volume to obtain a terbium organic composite nanoprobe for detecting fluoride ions in aqueous solution.

3. The method for preparing the terbium organic composite nanoprobe for fluoride ion detection in aqueous solution according to claim 2, characterized in that, The self-assembly promoters are: oleic acid, oleylamine, tri-n-octylphosphine, tri-n-octylphosphine oxide, cyclohexane, n-hexane, and petroleum ether.

4. The method according to any one of claims 1-3, characterized in that, The terbium organic composite nanoprobe, when excited by ultraviolet light of 250–400 nm, produces emission peaks with center wavelengths of 489–492, 544–547, 584–587, and 620–623 nm.

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