Application of B-CDs (at) EuBTC composite material

Abstract

The invention discloses application of a B-CDs (at) EuBTC composite material. The B-CDs (at) EuBTC composite material is used for qualitative and / or quantitative detection of p-aminophenol. The B-CDs (at) EuBTC composite material comprises a metal organic framework EuBTC and carbon dots loaded on the metal organic framework EuBTC, B-CDs represent blue light carbon dots, and BTC represents a ligand trimesic acid. The B-CDs (at) EuBTC composite material provided by the invention has excellent solvent stability, realizes ratio type fluorescence sensing on a biomarker p-aminophenol (PAP), has a detection limit of 0.65 mu M, and has the characteristics of good stability, high sensitivity, strong anti-interference performance, short response time and good cycle performance.

Description

TECHNICAL FIELD

[0001] The application relates to a metal organic framework B-CDs@EuBTC composite material, a preparation method thereof and application of the composite material in biomarker detection, and belongs to the technical field of metal organic framework (MOFs) materials. BACKGROUND

[0002] 4-Aminophenol (PAP) is an important organic intermediate and is widely used in the synthesis of dyes, drugs, photographic developers and the like. At the same time, it is one of the main metabolic products of acetaminophen (a commonly used non-prescription analgesic and antipyretic) in the human body, which can be excreted through the kidneys under normal dosage, and is converted into a toxic intermediate (such as N-acetyl-p-benzoquinone imine) when excessively taken, thereby causing liver and kidney function damage. Establishing a high-sensitivity detection method for 4-aminophenol has far-reaching significance for product quality control, environmental wastewater monitoring, drug research and development, human health and the like. Traditional detection methods have the limitations of complex operation and insufficient sensitivity, and therefore it is urgent to develop a rapid, sensitive and low-cost PAP detection sensing material.

[0003] In view of this, the application seeks to provide a use of a B-CDs@EuBTC composite material, which can realize ratio-type fluorescent sensing of a biomarker PAP through B-CDs peak enhancement and Eu 3+ peak weakening. SUMMARY

[0004] In order to overcome the shortcomings of the existing biomarker detection technology, the application provides a use of a B-CDs@EuBTC composite material, which can realize ratio-type fluorescent sensing of a biomarker PAP, and has the characteristics of good stability, high sensitivity, strong anti-interference, fast response time and good cycle performance.

[0005] To solve the above technical problems, the technical scheme adopted by the application is as follows:

[0006] A use of a B-CDs@EuBTC composite material for qualitative and / or quantitative detection of 4-aminophenol.

[0007] The B-CDs@EuBTC composite material comprises a metal organic framework EuBTC and carbon dots loaded on the metal organic framework EuBTC, wherein B-CDs represents blue light carbon dots, and BTC represents a ligand of trimesic acid.

[0008] The B-CDs@EuBTC composite material of the application is a MOFs fluorescent material and has good chemical stability.

[0009] The B-CDs@EuBTC composite material provided by the application has excellent detection performance on the biomarker p-aminophenol, and has the characteristics of good stability, high sensitivity, strong anti-interference, fast response time and good cycle performance.

[0010] In order to facilitate detection, the B-CDs@EuBTC composite material is used as a fluorescence probe to detect p-aminophenol in an aqueous solvent environment.

[0011] In the range of 0-40 μM, the relative luminescence intensity and the concentration of p-aminophenol satisfy a linear relationship: R / R0=0.09933x+1.1861 (the linear correlation coefficient is 0.99); wherein R0 represents the relative luminescence intensity of the composite material when no p-aminophenol is added, that is, the ratio of the luminescence intensities at 439 nm and 616 nm (I 439 nm / I 616 nm ); R represents the relative luminescence intensity of the sample containing p-aminophenol; and x is the concentration of p-aminophenol.

[0012] The B-CDs@EuBTC composite material realizes ratio-type fluorescence sensing on p-aminophenol, and the detection limit is 0.65 μM.

[0013] When the B-CDs@EuBTC composite material is used for detection of p-aminophenol, it has the characteristic of fast response time, and can reach stability within 20 s, realizing efficient detection of p-aminophenol.

[0014] The B-CDs@EuBTC composite material can be recycled: after one detection is completed, the B-CDs@EuBTC composite material is filtered, washed with water, dried, and recovered for next detection.

[0015] The B-CDs@EuBTC composite material provided by the application has good luminescence performance, and when excited at 272 nm, has a blue fluorescence emission peak of B-CDs at 439 nm and a red fluorescence emission peak of Eu 3+ has a fluorescence characteristic emission peak, and shows strong red light emission.

[0016] The preparation method of the B-CDs@EuBTC composite material is as follows: a mixed solution of Eu(NO3) 3· 6H2O and anhydrous sodium acetate is mixed with a trimesic acid solution, then a B-CDs solution is added, stirred at room temperature for 10-15 min, and then placed for 4-12 h, centrifuged, washed, and dried to obtain the B-CDs@EuBTC composite material.

[0017] In order to ensure the detection performance of the obtained material, the speed of the above centrifugation is 8000 rpm, the time is 8-12 min, water washing is adopted, and drying is 60℃ drying for 12 h.

[0018] In order to ensure that the detection is carried out efficiently and accurately, the preparation method of the B-CDs solution is as follows: glutamic acid is dissolved in water, stirred uniformly, and subjected to hydrothermal reaction, under the condition that the temperature is 170℃, the reaction is carried out for 6-10h, cooling, 0.22 μm filter membrane filtration, dialysis, and the B-CDs solution is obtained; wherein, the molecular weight cut-off of dialysis is 1000 Da, and the dialysis time is 12-24 h.

[0019] The concentration of the carbon dot precursor is specifically 0.05 mol / L.

[0020] The preparation of the carbon dots in the application does not need to use organic solvents, nor does it need to add catalysts such as sulfuric acid and phenylenediamine or other auxiliaries.

[0021] The mass ratio of the above glutamic acid to water is preferably (0.0065-0.0085):1.

[0022] The above Eu(NO3) 3· 6H2O and anhydrous sodium acetate are mixed in water, the concentration of Eu(NO3) 3· 6H2O is 0.02 mol / mL, the concentration of the anhydrous sodium acetate solution is 0.04 mol / mL; and the concentration of the trimesic acid solution is 0.02 mol / mL, and the solvent is ethanol.

[0023] In order to further improve the detection effect, the volume ratio of the mixed solution, the trimesic acid solution and the carbon dot solution is 1:1:(0.12-0.14).

[0024] The technologies not mentioned in the application all refer to the prior art.

[0025] Compared with the prior art, the application has the following beneficial effects:

[0026] (1) The B-CDs@EuBTC composite material provided by the application has good chemical stability, and the framework structure will not be damaged when it is soaked in various solvents.

[0027] (2) The B-CDs@EuBTC composite material provided by the application can efficiently detect the biomarker p-aminophenol, the detection limit is 0.65 μM, the response time is not more than 20 s, has high sensitivity and fast response speed, and thus realizes efficient and accurate detection.

[0028] (3) The B-CDs@EuBTC composite material provided by the application has strong anti-interference performance and rapid detection capability, and can be recycled. Attached Figure Description

[0029] Figure 1 is a scanning electron microscope image of the EuBTC and B-CDs@EuBTC composite material of the present invention;

[0030] Figure 2 shows the X-ray powder diffraction pattern of the EuBTC and B-CDs@EuBTC composite materials of the present invention;

[0031] Figure 3 is a high-resolution transmission electron microscope image of the EuBTC and B-CDs@EuBTC composite material of the present invention;

[0032] Figure 4 shows the X-ray powder diffraction pattern of the B-CDs@EuBTC composite material of the present invention after being immersed in various organic solvents;

[0033] Figure 5 shows the fluorescence spectrum of the B-CDs@EuBTC composite material of the present invention at room temperature;

[0034] Figure 6 shows the fluorescence spectra of the B-CDs@EuBTC composite material of the present invention in various urine components;

[0035] Figure 7 shows the fluorescence titration spectrum of p-aminophenol for the B-CDs@EuBTC composite material of the present invention;

[0036] Figure 8 shows the time-response fluorescence spectrum of the B-CDs@EuBTC composite material of the present invention to p-aminophenol;

[0037] Figure 9 shows a comparison of the fluorescence intensity of the B-CDs@EuBTC composite material of the present invention in urine chemicals containing and without p-aminophenol;

[0038] Figure 10 shows a comparison of the fluorescence intensity of the B-CDs@EuBTC composite material of the present invention after multiple cycles of detection of p-aminophenol. Detailed Implementation

[0039] To better understand the present invention, the following embodiments further illustrate the content of the present invention, but the content of the present invention is not limited to the following embodiments.

[0040] In all cases, 1,3,5-phenyltricarboxylic acid was purchased from Shanghai Shaoyuan Reagent Co., Ltd.; anhydrous sodium acetate was purchased from Beijing Mairuida Technology Co., Ltd.; glutamic acid was purchased from Anaiji (Shanghai) Pharmaceutical Chemical Co., Ltd.; all water used in the experiments was Wahaha purified water; unless otherwise specified, all experiments were conducted at room temperature (15~25°C); unless otherwise specified, all experiments were conducted at 300 r / min.

[0041] Example 1

[0042] Preparation of B-CDs@EuBTC composite material:

[0043] Step 1: Glutamic acid (0.0441 g) was dissolved in 6 mL water to form a mixed solution, which was treated by ultrasonic (300 W) until completely dissolved, and then transferred to a stainless steel Teflon-lined autoclave, which was heated at 170°C for 10 hours. After natural cooling to room temperature, the obtained product was filtered by a 0.22 μm filter membrane, and the filtrate was transferred to a dialysis bag (molecular weight cut-off 1000 Da) for dialysis for 24 hours to remove unreacted small molecular impurities, and finally a high-purity B-CDs solution was obtained.

[0044] Step 2: Eu(NO3) 3· 6H2O and anhydrous sodium acetate were dissolved in 45 mL water, and the concentration of Eu(NO3) 3· 6H2O was 0.02 mol / mL, and the concentration of anhydrous sodium acetate was 0.04 mol / mL; and trimesic acid (0.02 mol / mL) was dissolved in 45 mL ethanol, and the concentration of trimesic acid in the obtained ethanol solution was 0.02 mol / mL. The two solutions were mixed and immediately (within 1 min) added with 6 mL B-CDs solution, and after stirring at room temperature, it was left to stand for 12 hours. The obtained product was washed by water centrifugation (8000 rpm, 10 minutes) for 3 times, and dried at 60°C for 12 hours, and finally a B-CDs@EuBTC composite material was obtained.

[0045] Referring to Step 2, the only difference is that no B-CDs solution is added, and the rest is the same as Step 2, to obtain EuBTC.

[0046] Example 2

[0047] Morphology characterization of B-CDs@EuBTC composite material:

[0048] The morphology of the prepared B-CDs@EuBTC composite material was characterized, and the morphology of B-CDs@EuBTC and EuBTC was basically consistent, which was cluster-like, and the corresponding scanning electron microscope characterization was shown in Figure 1 .

[0049] Example 3

[0050] X-ray powder diffraction characterization of B-CDs@EuBTC composite material:

[0051] The prepared B-CDs@EuBTC composite material was characterized by X-ray powder diffraction, and its structure was consistent with that of EuBTC and its simulated spectrum, and the corresponding powder diffraction characterization was shown in Figure 2 .

[0052] Example 4

[0053] High-resolution transmission electron microscope image of B-CDs@EuBTC composite material:

[0054] like Figure 3 As shown, the B-CDs@EuBTC composite material retains the morphological characteristics of EuBTC, and the successful loading of carbon dots can also be clearly observed.

[0055] Example 5

[0056] Stability characterization of B-CDs@EuBTC composites:

[0057] Take 20 mg of B-CDs@EuBTC composite material and soak it in 2 mL of different solvents (water, N,N-dimethylformamide, methanol, ethanol, etc.). Figure 4 (Middle right figure) and different pH values ​​(pH=2, 4, 6, 8, 10, 12, corresponding to...) Figure 4 After being immersed in an aqueous solution (left image), dried, and characterized by powder diffraction (PXRD), its framework structure did not collapse, indicating good solvent stability. The corresponding powder diffraction characterization is shown in [Figure 1]. Figure 4 .

[0058] Example 6

[0059] Fluorescence performance characterization of B-CDs@EuBTC composites:

[0060] The liquid luminescence curves of B-CDs, EuBTC, and B-CDs@EuBTC composites were measured at room temperature using an F-7000 fluorescence spectrophotometer. The fluorescence spectra are shown below. Figure 5 At an excitation wavelength of 272 nm, the fluorescence spectrum of the B-CDs@EuBTC composite material exhibits significant characteristic peaks, with the characteristic emission peak of B-CDs at 439 nm and the characteristic emission peak of EuBTC at 616 nm. 3+ Characteristic emission peaks. Compared with the emission peaks of pure B-CDs, the emission peaks of B-CDs in the composite material exhibit a certain degree of blue shift.

[0061] Example 7

[0062] Fluorescence performance testing of B-CDs@EuBTC composite material in aqueous solutions containing various urine components:

[0063] The 2 mg of ground B-CDs@EuBTC sample was added into 3.0 mL of aqueous solution of urine chemicals (sodium chloride (NaCl), urea (Urea), sodium sulfate (Na2SO4), creatinine (Cre), creatine, glutamic acid (Glu), potassium chloride (KCl), ammonium chloride (NH4Cl), uric acid (UA) or PAP, with a concentration of 10 -3 M, respectively), and a stable suspension was formed after ultrasonic treatment for 10 minutes. The fluorescence spectrum of the suspension is shown in Fig. 2. Figure 6 Compared with the blank sample, the fluorescence spectrum of the suspension of NaCl, KCl, NH4Cl, Na2SO4, Urea, Glu, Cre, Creatine and UA did not change significantly, while the suspension of PAP showed the phenomenon of B-CDs peak enhancement and Eu 3+ characteristic peak weakening.

[0064] Example 8

[0065] Fluorescence titration experiment of B-CDs@EuBTC composite material on p-aminophenol (PAP):

[0066] The 2 mg of ground B-CDs@EuBTC sample was dispersed in 3.0 mL of aqueous solution, and a stable suspension was formed after ultrasonic treatment for 10 minutes. A certain volume of PAP aqueous solution (concentration of 1×10 -3 M) was gradually added into the suspension. With the increase of PAP concentration, the phenomenon of B-CDs peak enhancement and Eu 3+ characteristic peak weakening was gradually observed, and the experimental data obtained are shown in Fig. 3. Figure 7 At low concentration, the relative luminescence intensity R (R=I 439 nm / I 616 nm ) was linearly related to the concentration of PAP, R / R0 = 0.09933x +1.1861 (linear correlation coefficient was 0.99); wherein, R0 represented the relative luminescence intensity of the composite material without adding p-aminophenol, i.e. the ratio of luminescence intensity at 439 nm and 616 nm (I 439 nm / I 616 nm ); R represented the relative luminescence intensity of the sample after adding p-aminophenol; x was the concentration of p-aminophenol. The limit of detection (LOD) of PAP was calculated to be 0.65 µM by using 3δ / k method (δ: standard deviation of 10 blank samples; k: slope of the calibration curve).

[0067] Example 9

[0068] Fluorescence time response experiment of B-CDs@EuBTC composite material to p-aminophenol (PAP):

[0069] 2 mg of B-CDs@EuBTC sample was dispersed in 3.0 mL of water to form a stable suspension, and 100 μL of PAP solution with a concentration of 1 × 10 -3 M was added. The fluorescence signal of the sample reached a stable state within 20 s, showing a fast response speed. The experimental data are shown in Figure 8 .

[0070] Example 10

[0071] Anti-interference experiment of B-CDs@EuBTC composite material to p-aminophenol (PAP):

[0072] 2 mg of B-CDs@EuBTC sample was dispersed in 1.5 mL of different urine compound aqueous solution (creatinine (Cre), glutamic acid (Glu), potassium chloride (KCl), sodium sulfate (Na2SO4), sodium chloride (NaCl), ammonium chloride (NH4Cl), uric acid, urea, creatine) with a concentration of 2 × 10 -3 M, and 1.5 mL of water was used as a blank test (Black). Then 1.5 mL of PAP aqueous solution with a concentration of 2 × 10 -3 M was added to each solution to form a stable suspension after ultrasonic treatment. The fluorescence spectra of each solution before and after the addition of PAP were tested. When PAP coexists with other urine compounds, the system can still maintain the significant enhancement of the B-CDs characteristic peak and the weakening of the Eu 3+ characteristic peak, indicating that the composite material has excellent anti-interference ability. The experimental data are shown in Figure 9 .

[0073] Example 11

[0074] Detection cycle experiment of B-CDs@EuBTC composite material to p-aminophenol (PAP):

[0075] 2 mg of B-CDs@EuBTC sample was dispersed in PAP aqueous solution (3.0 mL, 10 -3 M) to form a suspension, and the fluorescence spectrum was tested. After centrifugation, the solid was washed with water and dispersed in PAP aqueous solution (3.0 mL, 10 -3 M) again. The fluorescence spectrum of the obtained suspension was tested, and this cycle was repeated five times. The material still maintained a relatively stable fluorescence response, confirming its good repeatability. The experimental data are shown in Figure 10 .

[0076] Application Example

[0077] Preparation of simulated urine (The simulated urine is composed of 3.333 g・L -1 urea, 0.177 g・L -1 creatine, 1.000 g・L -1 chloride ion (Cl - ), 1.000 g・L -1 potassium ion (K + ), 0.025 g・L -1 phosphate ion (PO4 3- ), 0.300 g・L -1 sulfate ion (SO4 2- ), 0.025 g・L -1 calcium ion (Ca 2+ ), 0.0167 g・L -1 magnesium ion (Mg 2+ ), 0.167 g・L -1 sodium ion (Na + ), 0.025 g・L -1 ammonium ion (NH4 + ) and 0.167 g・L -1 carbonate ion (CO3 2- ) and diluted 100 times, a certain concentration of PAP is added, and the recovery rate is calculated by standard addition method. The recovery rate of PAP is 98.51%-101.75%, indicating that the ratio fluorescence sensing method has high accuracy and reliability, and can be used for the analysis and detection of PAP in actual samples. The detected data results are shown in Table 1.

[0078] Table 1 Detection of the effect of B-CDs@EuBTC on PAP in simulated urine.

[0079]

[0080] [a] All concentrations are expressed as the average of three measurements - standard deviation (SD). [b] The relative standard deviation (RSD) is defined as (SD / average) x 100%.

[0081] Comparative Example 1

[0082] Different from Example 1: in step 1, after adding 2 mL of concentrated sulfuric acid to the mixed solution, ultrasonic treatment was performed again, and the rest was according to Example 1. Result: the carbon dots have a fluorescence emission peak at 499 nm, and the fluorescence intensity is low. Compared with the carbon dots of the present patent, there is a red shift, and the crystal structure of the loaded carbon dots collapses.

[0083] Comparative Example 2

[0084] The difference from Example 1 is that: replace water in step 1 with formamide, and add 0.0220 g of o-phenylenediamine, and the rest is according to Example 1. Result: the carbon dots have fluorescence emission peaks at 342 nm and 554 nm, the fluorescence intensity is low, and the crystal structure collapses after the carbon dots are reloaded.

[0085] Comparative Example 3

[0086] The difference from Example 1 is that: reduce the amount of glutamic acid to 0.022 g, and the rest is according to Example 1. Result: the fluorescence intensity is doubled compared with the carbon dots of the patent, but the composite material after reloading the carbon dots only has the characteristic peak of EuBTC, and there is no obvious carbon dot peak.

[0087] Comparative Example 4

[0088] The difference from Example 1 is that: increase the amount of glutamic acid to 0.0882 g, and the rest is according to Example 1. Result: there is a red shift in the emission peak of the carbon dots compared with the carbon dots of the patent, but the composite material after reloading the carbon dots only has the characteristic peak of EuBTC, and there is no obvious carbon dot peak.

[0089] Comparative Example 5

[0090] The difference from Example 1 is that: the reaction temperature in step 1 is increased to 200°C, and the rest is according to Example 1. Result: there is a red shift in the emission peak of the carbon dots compared with the carbon dots of the patent, but the composite material after reloading the carbon dots only has the characteristic peak of EuBTC, and there is no obvious carbon dot peak.

[0091] Comparative Example 6

[0092] The difference from Example 1 is that: the reaction temperature in step 1 is reduced to 150°C, and the rest is according to Example 1. Result: the fluorescence intensity is doubled compared with the carbon dots of the patent, but the composite material after reloading the carbon dots only has the characteristic peak of EuBTC, and there is no obvious carbon dot peak.

Claims

1. An application of a B-CDs@EuBTC composite material, characterized in that, Used for qualitative and / or quantitative detection of p-aminophenol; The B-CDs@EuBTC composite material includes a metal-organic framework EuBTC and carbon dots loaded on the metal-organic framework EuBTC, wherein B-CDs represents blue carbon dots and BTC represents the ligand pyromellitic acid.

2. The use of the B-CDs@EuBTC composite material according to claim 1, characterized in that, B-CDs@EuBTC composite material was used as a fluorescent probe for the fluorescence detection of p-aminophenol in an aqueous solvent environment.

3. The use of the B-CDs@EuBTC composite material according to claim 1 or 2, characterized in that, The relative luminescence intensity and the concentration of p-aminophenol satisfy a linear relationship: R / R0 = 0.09933x + 1.1861; where R0 represents the relative luminescence intensity of the composite material without the addition of p-aminophenol, i.e., the ratio of the luminescence intensity at 439 nm to that at 616 nm (I 439 nm / I 616 nm R represents the relative luminescence intensity of the sample containing p-aminophenol; x is the concentration of p-aminophenol.

4. The use of the B-CDs@EuBTC composite material according to claim 1 or 2, characterized in that, A ratiometric fluorescence sensor for p-aminophenol was developed, with a detection limit of 0.65 μM.

5. The use of the B-CDs@EuBTC composite material according to claim 1 or 2, characterized in that, The fluorescence response of p-aminophenol stabilizes within 20 seconds.

6. The use of the B-CDs@EuBTC composite material according to claim 1 or 2, characterized in that, B-CDs@EuBTC composite material is recyclable: after each test, the B-CDs@EuBTC composite material is filtered, washed, dried, and recycled for the next test.

7. The use of the B-CDs@EuBTC composite material according to claim 1 or 2, characterized in that, The preparation method of B-CDs@EuBTC composite material is as follows: Eu(NO3) 3· A mixed solution of 6H2O and anhydrous sodium acetate was mixed with a solution of trimesic acid, and then a B-CDs solution was added. The mixture was stirred at room temperature for 10-15 minutes, allowed to stand for 4-12 hours, centrifuged, washed, and dried to obtain the B-CDs@EuBTC composite material.

8. The use of the B-CDs@EuBTC composite material according to claim 7, characterized in that, The preparation method of B-CDs solution is as follows: glutamic acid is dissolved in water, stirred evenly, and subjected to hydrothermal reaction at a temperature of 170℃ for 6-10 h. After cooling, the solution is filtered through a 0.22 μm filter membrane and dialyzed to obtain B-CDs solution. The molecular weight cutoff for dialysis is 1000 Da, and the dialysis time is 12-24 h.

9. The use of the B-CDs@EuBTC composite material according to claim 7, characterized in that, Eu(NO3) 3· In a mixed solution of 6H2O and anhydrous sodium acetate, the solvent is water, and the solvent is Eu(NO3). 3· The concentration of 6H2O was 0.02 mol / mL, the concentration of anhydrous sodium acetate solution was 0.04 mol / mL, the concentration of trimesic acid solution was 0.02 mol / mL, and the solvent was ethanol.

10. The use of the B-CDs@EuBTC composite material according to claim 7, characterized in that, The volume ratio of the mixed solution, pyromellitic acid solution, and carbon dot solution is 1:1:(0.12~0.14).

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