Two-dimensional Cu-CP fluorescent probe material and preparation method and application thereof for recognizing Fe 3+ ​

Abstract

The application discloses a two-dimensional Cu-CP fluorescent probe material, a preparation method thereof and application of the two-dimensional Cu-CP fluorescent probe material in recognizing Fe 3+ , and belongs to the field of fluorescent sensing materials. The structural formula of the two-dimensional Cu-CP fluorescent probe is [CuL2] n , wherein L − is a 4-(3, 5-dimethyl-1H-pyrazol-1-yl) benzoate anion. The two-dimensional Cu-CP fluorescent probe material has the advantages of simple preparation method, high yield, low cost and good fluorescent stability, and when the two-dimensional Cu-CP fluorescent probe material is used for detecting Fe 3+ in water, the two-dimensional Cu-CP fluorescent probe material has excellent recognition performance, and good sensitivity and anti-interference performance.

Description

Technical Field

[0001] This invention belongs to the field of fluorescent sensing materials, and specifically relates to a two-dimensional Cu-CP fluorescent probe material, its preparation method, and its ability to identify Fe. 3+ Applications. Background Technology

[0002] In recent years, metal ions have inevitably been used in the textile industry, bio-antibacterial disinfection, and other fields, causing their diffusion in nature and posing a threat to both the environment and human health. While instruments and methods for metal ion detection have seen some development, they are generally complex to operate and have long detection cycles, hindering timely and rapid detection of pollutants in daily life and production. Iron is the most abundant trace element in the human body after silicon; iron deficiency can lead to anemia, difficulty breathing, and even heart failure. Excessive iron intake can induce cancer, liver disease, and immune system disorders. Therefore, iron ion detection has become an important means of protecting the environment and human health. Organometallic coordination polymers possess unique chemical properties, and as fluorescent probe materials in the field of chemical sensors, they exhibit advantages such as high sensitivity, low detection limit, ease of operation, and recyclability for metal ion recognition. Summary of the Invention

[0003] The purpose of this invention is to provide a two-dimensional Cu-CP fluorescent probe material, its preparation method, and its ability to identify Fe. 3+ Applications. This Cu-CP fluorescent probe material is used for the detection of Fe in water. 3+ The detection exhibits high sensitivity, stability, anti-interference ability, and recyclability, and the preparation method is simple, low-cost, and environmentally friendly.

[0004] The technical solution adopted in this invention is as follows: A two-dimensional Cu-CP fluorescent probe material with the molecular formula: [CuL2] n .

[0005] Among them, L − It is an anion formed by the loss of a proton from the ligand 4-(3,5-dimethyl-1H-pyrazol-1-yl)benzyl (HL).

[0006] A schematic diagram of the two-dimensional layered structure of the two-dimensional Cu-CP fluorescent probe material is shown below. Figure 1 As shown; it is in Z = 4 orthorhombic crystal system Pbca Crystallization in space group, unit cell parameters: a =9.2367(14) Å, b = 15.658 Å, c = 15.658(2) Å, α =90°, β= 90°, γ = 90°.

[0007] The preparation method of the above-mentioned two-dimensional Cu-CP fluorescent probe material includes the following steps: A1. At room temperature, soluble copper salt, ligand HL and KOH solid are dissolved in a mixed solvent of deionized water and MeOH and stirred for 2-5 hours to obtain a blue solution. Preferably, the molar ratio of soluble copper salt, ligand HL, and KOH is 1:1.5~2:1.5~4.

[0008] Preferably, the molar concentrations of the soluble copper salt, ligand HL, and KOH in the mixed solvent of deionized water and MeOH in the reaction system are 0.04~0.09 mol / L.

[0009] Preferably, the volume ratio of MeOH to deionized water in the mixed solvent is 1:0.6~1.5.

[0010] Preferably, the soluble copper salt is any one of copper chloride, copper acetate, and copper nitrate.

[0011] A2. Pour the blue solution obtained in A1 into a small sample vial, then place the small sample vial into a large sample vial containing ether, seal the large sample vial, and let it stand at room temperature until the ether diffuses into the small sample vial until dark blue crystals precipitate.

[0012] A3. The product obtained in A2 is filtered through a microporous membrane, washed, and dried to obtain Cu-CP fluorescent probe material.

[0013] Preferably, the pore size for filtration described in A3 is [size to be specified].

[0014] Preferably, the solvent used for washing is a mixture of deionized water and ethanol with a volume ratio of 4:3 to 1:1, and the number of washing cycles is 2 to 5.

[0015] This invention also provides the above-mentioned two-dimensional Cu-CP fluorescent probe material as a fluorescent sensor in Fe 3+ Applications in ion detection.

[0016] Specifically, the detection method includes the following steps: S1. Grind the Cu-CP fluorescent probe material, disperse it in deionized water, sonicate it to form a suspension, and measure its fluorescence excitation and emission spectra; S2, Preparation of Fe 3+ Ionized aqueous solution, and the prepared Fe was pipetted into the solution. 3+ An ion-soluble aqueous solution was added to the Cu-CP material suspension obtained in step S1, and its fluorescence emission intensity was measured to obtain the fluorescence response intensity of Cu-CP and Fe.3+ The relationship between ion concentrations is used to test Fe in a sample. 3+ The concentration of ions.

[0017] Preferably, in step S1, the mass ratio of Cu-CP material to water in the Cu-CP material suspension is 1:500 to 1000.

[0018] Preferably, the Cu-CP material described in step S1 is ground in a ball mill for 10 to 30 minutes.

[0019] Preferably, the ultrasonic dispersion time in step S1 is 0.5–2 h, and the power is 50–70 Hz.

[0020] The two-dimensional Cu-CP fluorescent probe material provided by this invention has good fluorescence intensity and stability, and can be used for qualitative and quantitative detection of Fe in water. 3+ Ions. Compared with existing detection methods, it exhibits superior sensitivity, selectivity, and anti-interference ability. Attached Figure Description

[0021] Figure 1 A schematic diagram of the two-dimensional layered structure of Cu-CP fluorescent probe material; Figure 2 X-ray powder diffraction pattern of Cu-CP fluorescent probe material; Figure 3 Infrared spectrum of Cu-CP fluorescent probe material; Figure 4 Thermogravimetric curve of Cu-CP fluorescent probe material; Figure 5 Fluorescence emission spectrum of Cu-CP fluorescent probe material suspension and its effect on different concentrations of Fe 3+ Fluorescence response spectrum of ions; Figure 6 A bar chart comparing the fluorescence intensity of Cu-CP fluorescent probe material suspension before and after the addition of various metal ions. Figure 7 A bar chart showing the fluorescence intensity comparison before and after adding various metal ions to the Cu-CP fluorescent probe material suspension under different interfering metal ion conditions. Figure 8 The fluorescence intensity of Cu-CP fluorescent probe material suspension and Fe 3+ Linear relationship graph of ion concentration. Detailed Implementation

[0022] This invention is not limited to the specific embodiments listed below. Those skilled in the art can implement this invention using various other specific embodiments based on the content disclosed herein. Any modifications or alterations made to the design structure and concept of this invention fall within the protection scope of this invention. It should be noted that, unless otherwise specified, the embodiments and features described in this invention can be combined with each other. Example 1

[0023] The preparation method of Cu-CP fluorescent probe material includes the following steps: At room temperature, CuCl₂·2H₂O (0.0340 g, 0.2 mmol), HL (0.0432 g, 0.20 mmol), and KOH (0.0168 g, 0.30 mmol) were dissolved in 4 mL of deionized water and 4 mL of MeOH. The mixture was stirred for 5 h to obtain a clear blue solution. This solution was poured into a small sample vial, which was then placed inside a large sample vial containing diethyl ether. The large vial was sealed, and the vial was allowed to stand at room temperature for 10 days to allow the ether to diffuse into the small vial. A deep blue product precipitated after this period. The product was then processed through a 22mm sieve. μ The sample was collected by filtration through a filter membrane, and then washed twice each with 8 mL of deionized water and 6 mL of ethanol. After drying, Cu-CP fluorescent probe material was obtained with a yield of 78%. Example 2

[0024] At room temperature, CuCl₂·2H₂O (0.0170 g, 0.1 mmol), HL (0.0324 g, 0.15 mmol), and KOH (0.0112 g, 0.20 mmol) were dissolved in 3 mL of deionized water and 3 mL of MeOH, and stirred for 3 h to obtain a clear blue solution. The resulting blue solution was poured into a small sample vial, which was then placed inside a large sample vial containing diethyl ether. The large sample vial was sealed, and the solution was allowed to stand at room temperature for 8 days to allow the diethyl ether to diffuse into the small sample vial. After standing at room temperature for 8 days, a deep blue product precipitated. The obtained product was then processed through a 22mm pore size filter. μ The product was collected by filtration through a filter membrane and washed twice with 8 mL of deionized water and 6 mL of ethanol, respectively. After drying, Cu-CP fluorescent probe material was obtained with a yield of 72%. Example 3

[0025] At room temperature, Cu(NO3)2·3H2O (0.0242 g, 0.1 mmol), HL (0.0216 g, 0.1 mmol), and KOH (0.0112 g, 0.20 mmol) were dissolved in 4 mL of deionized water and 6 mL of MeOH. The mixture was stirred for 4 h to obtain a clear blue solution. The resulting blue solution was poured into a small sample vial, which was then placed inside a large sample vial containing diethyl ether. The large sample vial was sealed, and the solution was allowed to stand at room temperature for 12 days to allow the diethyl ether to diffuse into the small sample vial. After standing at room temperature for 12 days, a deep blue product precipitated. The obtained product was then processed using a filter with a pore size of 22 mm. μ The product was collected by filtration through a filter membrane of m, washed twice with 6 mL of deionized water and ethanol respectively, and dried to obtain Cu-CP fluorescent probe material with a yield of 70%. Example 4

[0026] At room temperature, Cu(CH3COO)2·H2O (0.0399 g, 0.2 mmol), HL (0.0432 g, 0.20 mmol), and KOH (0.0168 g, 0.30 mmol) were dissolved in 6 mL of deionized water and 4 mL of MeOH. The mixture was stirred for 3 h to obtain a clear blue solution. This solution was poured into a small sample vial, which was then placed inside a large sample vial containing diethyl ether. The large vial was sealed, and the solution was allowed to stand at room temperature for 12 days to allow the ether to diffuse into the small vial. A deep blue product precipitated after standing at room temperature for 12 days. The solution was analyzed using a 22mm pore size... μ The product obtained above was collected by filtration through a filter membrane of m, washed twice with 6 mL of deionized water and ethanol respectively, and dried to obtain Cu-CP fluorescent probe material with a yield of 75%.

[0027] The Cu-CP fluorescent probe materials prepared in Examples 1-4 of this invention are the same, only the yields are different. Performance testing experiments were conducted on the Cu-CP fluorescent probe materials.

[0028] Figure 1 This is an X-ray diffraction pattern of a Cu-CP fluorescent probe material. Figure 1 As shown, in Cu-CP materials, L − In the ligand ions, the N atom on the pyrazole ring and the oxygen atom on the carboxyl group of the benzene ring both participate in the coordination of copper ions. Under their influence, Cu1 is connected with four surrounding copper ions (Cu1C, Cu1D, Cu1E and Cu1F) to form a two-dimensional (4, 4) layered structure.

[0029] Powder diffraction analysis of the phase purity of Cu-CP fluorescent probe materials was performed at room temperature, such as... Figure 2 As shown, a large number of Cu-CP products exhibit good phase purity, and their peaks largely correspond to and match the simulated peaks. The infrared spectral analysis of the Cu-CP fluorescent probe materials was conducted by... Figure 3 As shown, at 1588 cm -1 and 1410 cm -1 The characteristic peak at L is - The asymmetric and symmetric stretching vibration peaks of the carboxylate ion are observed at 1367 cm⁻¹. –1 The strong peak at that location corresponds to L - The conjugate C=N stretching vibration in the ion.

[0030] Thermogravimetric analysis was performed on the Cu-CP fluorescent probe material. Figure 4 It can be seen that the weight of the Cu-CP material remains essentially unchanged in the range of 0-270 ℃ as the temperature increases, exhibiting good thermal stability. In the 270-315 ℃ range, it loses 43.9% of its weight, according to the complex chemical formula [CuL2]. n The calculation is equivalent to losing 1 L. − The ligand ion has a theoretical value of 43.7%. The remaining structure then decomposes continuously until it stabilizes at 756 °C. The remaining 16.9% by weight is equivalent to one CuO, with a theoretical value of 16.0%.

[0031] Fluorescence emission spectroscopy detection: Cu-CP was thoroughly ground and dispersed in deionized water, then sonicated for 30 min to obtain a suspension with a concentration of approximately 1 mg / mL. After standing for 5 min, the suspension remained unchanged. 2 mL of the suspension was then subjected to fluorescence analysis. Figure 5 As shown, the Cu-CP suspension exhibits a maximum emission wavelength of 360 nm when the excitation wavelength is 300 nm.

[0032] Fluorescence detection experiment: At room temperature, 30 mg of Cu-CP powder sample was milled in a ball mill for 5 min, then dispersed in 30 mL of deionized water and sonicated for another 30 min to obtain a uniformly dispersed suspension (1 mg / mL). 1 mL of a 5 × 10⁻⁶ concentration was then taken. -3 mol / L nitrate aqueous solution M(NO3) x (M = Cu, Ba, Na, Ca, Ni, Zn, Pb, K, Cd, Fe, Hg, Co, Mn, Cr, Sr, Dy, Sm, Ce, Yb, La, and Er; x = 1, 2, and 3), each was added to 2 mL of the above coordination polymer suspension, sonicated for 30 s, and allowed to stand for 5 min. The fluorescence emission spectra of the resulting suspensions were then measured. Figure 6 It can be seen that the fluorescence intensity of the coordination polymer changes slightly after the addition of most ions, but the change is negligible. However, Fe... 3+The addition of ions quenches the fluorescence of Cu-CP, with a quenching efficiency of 97.35%. Therefore, Cu-CP has a significant effect on the fluorescence of Fe. 3+ The ion recognition exhibits excellent selectivity. Even in the presence of interfering ions, the Cu-CP fluorescent probe material shows excellent selectivity for Fe. 3+ Ion recognition is almost unaffected. Figure 7 This indicates that the material affects the Fe in water. 3+ The detection of ions all exhibits good anti-interference capabilities.

[0033] Fe 3+ Ion concentration detection: Take 1 mL of Fe at different concentrations 3+ An ion-containing aqueous solution was added to 2 mL of Cu-CP suspension, sonicated for 30 s, and allowed to stand for 5 min. The fluorescence emission spectrum of the resulting suspension was then measured. Figure 5 As shown, with Fe 3+ With increasing ion solution concentration, the emission intensity of the Cu-CP fluorescent probe material was observed to decrease continuously. The relative fluorescence intensity ratio ( I 0 / I )-1 and C Fe3+ Linear relationship Figure 8 This indicates that it can quantitatively detect Fe in water. 3+ ion, K sv (Fe 3+ ) = 7.42 × 10 4 M −1 , R 2 = 0.96912, from the formula LOD (limit of detection) = 3 σ / k Calculations show that Cu-CP affects Fe 3+ The detection limit for ion recognition is 1.03 × 10⁻⁶. -5 M.

[0034] In summary, this invention designs and synthesizes a novel two-dimensional layered Cu-CP fluorescent probe material for the specific detection of Fe in water. 3+ This method offers advantages such as rapid detection, high sensitivity, thermal stability, and anti-interference capabilities. Furthermore, it is simple to prepare, low in cost, produces minimal pollution, and is easy to operate.

[0035] The above-described embodiments are merely preferred experimental schemes of the present invention. It should be noted that, for those skilled in the art, the experimental schemes may be described in different ways, and appropriate modifications may be made to the embodiments of the present invention, but all of these modifications are within the protection scope of the present invention.

Claims

1. A two-dimensional Cu-CP fluorescent probe material, characterized in that: The molecular formula of the two-dimensional Cu-CP fluorescent probe is: [CuL2] n L − It is an anion formed by the loss of a proton from the ligand 4-(3,5-dimethyl-1H-pyrazol-1-yl)benzoic acid (HL); the two-dimensional Cu-CP fluorescent probe belongs to the orthorhombic crystal system. Z =4, space group is Pbca Unit cell parameters: a =9.2367(14) Å, b = 15.658 Å, c = 15.658(2) Å, α = 90°, β = 90°, γ = 90°.

2. A method for preparing a two-dimensional Cu-CP fluorescent probe material as described in claim 1, characterized in that: Includes the following steps: A1. At room temperature, soluble copper salt, ligand HL, and KOH solids are dissolved in a mixed solvent of deionized water and methanol, and stirred for 2-5 hours to obtain a blue solution; wherein the volume ratio of methanol to deionized water in the mixed solvent is 1:0.6-1.5; and the total molar concentration of soluble copper salt, ligand HL, and KOH in the mixed solvent of deionized water and methanol is 0.04-0.09 mol / L. A2. Pour the blue solution obtained in A1 into a small sample bottle, then place the small sample bottle into a large sample bottle containing ether, seal the large sample bottle, and let it stand at room temperature until the ether diffuses into the small sample bottle until dark blue crystals precipitate. A3. The product obtained in A2 is filtered through a microporous membrane, washed, and dried to obtain a two-dimensional Cu-CP fluorescent probe material.

3. The method for preparing the two-dimensional Cu-CP fluorescent probe material according to claim 2, characterized in that: The soluble copper salts mentioned in A1 are Cu(NO3)2·3H2O, Cu(CH3COO)2·H2O, or CuCl2·2H2O.

4. The method for preparing the two-dimensional Cu-CP fluorescent probe material according to claim 2, characterized in that: The molar ratio of soluble copper salt, ligand HL, and KOH is 1:1.5~2:1.5~4.

5. An application of the two-dimensional Cu-CP fluorescent probe material as described in claim 1, characterized in that: The Cu-CP fluorescent probe material was used as a fluorescent sensor in water containing Fe. 3+ Applications in detection.

6. The application of the two-dimensional Cu-CP fluorescent probe material according to claim 5, characterized in that: Specifically, the steps include the following: S1. Grind the two-dimensional Cu-CP fluorescent probe material, disperse it in deionized water, sonicate it to form a suspension, and measure its fluorescence excitation and emission spectra; S2, Fe 3+ An aqueous solution was added to the two-dimensional Cu-CP material suspension obtained in step S1, and its fluorescence emission intensity was measured to obtain the fluorescence response intensity of Cu-CP and Fe. 3+ The relationship between concentrations is used to test the Fe content in a sample. 3+ The concentration.

7. The application of the two-dimensional Cu-CP fluorescent probe material according to claim 6, characterized in that: In step S1, the mass ratio of the two-dimensional Cu-CP fluorescent probe material to deionized water in the suspension is 1:500 to 1000.

8. The application of the two-dimensional Cu-CP fluorescent probe material according to claim 6, characterized in that: The two-dimensional Cu-CP fluorescent probe material described in step S1 is ground using a ball mill for 10–30 min.

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