Gel bis-pyrenyl fluorescent probe, preparation method thereof and application of gel bis-pyrenyl fluorescent probe in detection and removal of cadmium

Abstract

The invention discloses a gel bis-pyrenyl fluorescent probe, a preparation method thereof and application of the gel bis-pyrenyl fluorescent probe in detection and removal of cadmium, and the probe can be complexed with Cd < 2 + > in a 5% DMSO solvent, so that the fluorescence of the probe is enhanced. The probe molecule PYRX can qualitatively and quantitatively detect Cd < 2 + > in a real sample, has the characteristics of quick response and low detection limit, and has better stability under a wide pH condition, so that the probe molecule PYRX has important application value in the fields of biochemistry and the like. Meanwhile, a probe PYRX-loaded agarose gel PYRX-aga is constructed, and Cd < 2 + > in a food sample can also be qualitatively and quantitatively detected. As the agarose gel has a large number of apertures, the PYRX-aga is applied to adsorption removal of Cd < 2 + > in a solution. In the removal process, the PYRX-aga device can show a good fluorescence / colorimetric effect, and the removal efficiency can reach 96% or above. # imgabs0 #

Description

Technical Field

[0001] The present invention belongs to the field of fluorescence detection and relates to the detection of Cd 2+ Fluorescent probes and their applications in agarose gel detection and removal, particularly a method for quantitatively detecting Cd 2+ Fluorescent probe and preparation method and application thereof. Background Art

[0002] Cadmium ions (Cd 2+ ) is a heavy metal ion widely used in industry and agriculture. It is widely used in nickel batteries, alloys, electroplating, metallurgy and phosphate fertilizers. In the production process, a large part of Cd 2+ Cannot be effectively recycled, thus resulting in Cd 2+ Large amounts of exposure to the environment increase Cd 2+ Percentage of Cd in the human food web. 2+ It mainly enters the human environment through wastewater and pollutes food by irrigating crops. Among them, rice is a typical "victim crop". 2+ It enters the human body through the food chain and causes carcinogenic effects on the kidneys, lungs, bones and nervous system. The half-life of cadmium is very long (10-30 years), and it ranks seventh among the dangerous substances in the WHO. The US Environmental Protection Agency also lists Cd 2+ It is listed as one of the 126 major pollutants. WHO stipulates that Cd in drinking water 2+ The maximum residual amount is 3ppb. Therefore, the detection of Cd in food and environment 2+ The content is of great significance.

[0003] Currently, the detection of Cd 2+ There are many analytical techniques for Cd, such as solvent and solid phase extraction, chemical precipitation, ion exchange, electrocoagulation and membrane separation. However, these techniques are complex in sample pretreatment, cannot be removed by adsorption, have high energy consumption, poor performance when reused, and poor selectivity. Fluorescence spectroscopy has the advantages of high sensitivity, good specificity, and fast response time. Fluorescence spectroscopy is used to detect Cd 2+ It has certain application prospects. Researchers are developing a method for detecting Cd 2+ Considerable efforts have been made in the development of fluorescent probes for the dual detection of Cd. 2+ and Hg 2+ , in water system to Cd 2+ (on) and Hg 2+ (off) has the opposite fluorescence response. There are also coumarin-amide-dipyridylamine-based fluorescence acceptors that respond to Zn 2+ and Cd 2+However, these probes cannot be reused in subsequent experiments, have low sensitivity, and cannot be removed by adsorption. Therefore, it is highly desirable to develop a simple, highly selective, and fast-response fluorescent probe for the detection and removal of Cd. 2+ . Summary of the invention

[0004] The present invention provides a gel bispyrene-based fluorescent probe and a preparation method thereof and a method for detecting and removing Cd 2+ Application in.

[0005] One of the purposes of the present invention is to provide a fluorescent probe with simple synthesis route, mild reaction conditions and low cost; the second purpose is to provide a fluorescent probe with high sensitivity, good selectivity and strong anti-interference ability, which can accurately identify Cd in complex systems. 2+ The fluorescent probe has the following structure:

[0006]

[0007] Its synthetic route is:

[0008]

[0009] Specific synthesis method: 1-aminopyrene and p-dibenzaldehyde are taken in anhydrous ethanol, the reaction solution is heated to reflux, and the reaction is monitored by a plate. After the reaction is complete, it is cooled to room temperature and the solvent is removed by rotary evaporation to obtain an orange crude product. The crude product is purified by column chromatography using DCM / PE (v / v, 1:1) as an eluent to obtain an orange solid probe PYRX.

[0010] The silica gel used in column chromatography is 200-300 mesh, and the eluent is: V 二氯甲烷 / V 石油醚 =1 / 1.

[0011] The mechanism of the probe of the present invention is as follows:

[0012]

[0013] The mechanism of action of the fluorescent probe of the present invention is as follows: PYRX has two Schiff base structures, which are Cd 2+ The coordination with the probe provides a coordination site, thereby turning on the probe fluorescence in solution (5% DMSO) (detection limit: 23.15 nmol / L), and forming a coordination compound PYRX+Cd at a ratio of 2:1. 2+ .

[0014] The fluorescent probe is used in the preparation of qualitative and quantitative detection of Cd 2+ The application of the reagent is as follows: the fluorescent probe PYRX is dissolved in DMSO solvent to prepare (0.5-2)×10-4 (The most preferred is 1×10 -4 )mol / L probe solution, then add the substance to be tested, and observe the fluorescence change at 340nm through fluorescence detection after the reaction.

[0015] The fluorescent probe is used to prepare the quantitative detection of Cd 2+ The steps are as follows: dissolving the fluorescent probe PYRX in DMSO to prepare a fluorescent probe PYRX concentration of 1.0×10 -6 mol / L solution, then add the sample to be tested, detect the fluorescence intensity, and quantitatively calculate the Cd based on the linear relationship between the fluorescence intensity and the concentration of the sample to be tested. 2+ The content.

[0016] The probe is used to prepare agarose gel for quantitative detection of Cd 2+ The steps are as follows: 2 g of agarose is poured into ultrapure water, heated until the agarose is completely dissolved and the solution is clear, then the heating is turned off, and then 600 μL of the probe mother solution and 2.40 mL of DMSO are added and stirred continuously. After stirring evenly, the mixture is quickly poured into a beaker and cooled to room temperature to obtain PYRX-aga agarose gel. 2+ Add it dropwise on the surface of PYRX-aga, wait for the reaction to be complete, and then take fluorescence / colorimetric photos with a camera under a handheld UV lamp / sunlight.

[0017] The probe is used to prepare agarose gel for adsorption and removal of Cd 2+ The steps are as follows: placing agarose gel (PYRX-aga) in different concentrations (0.01, 0.10, 1.00, 10, 50, 100 μmol / L) of Cd 2+ Stir in the solution. After the reaction is complete, remove it. ICP-MS method is used to determine the Cd content in the solution before and after removal. 2+ The concentration change was measured and the removal rate was calculated.

[0018] Compared with the prior art, the present invention has the following advantages:

[0019] The probe of the present invention can react with Cd in 5% DMSO solvent. 2+ Complexation. The fluorescence of the probe is enhanced. The probe molecule PYRX of the present invention can qualitatively and quantitatively detect Cd in real samples. 2+ It has the characteristics of fast response (190s), low detection limit (23.10nmol / L) and good stability under wide pH conditions (pH 2-11), so it has important application value in biochemistry and other fields. At the same time, the probe PYRX-loaded agarose gel PYRX-aga was constructed, which can also qualitatively and quantitatively detect Cd in food samples.2+ Since agarose gel has a large number of pores, PYRX-aga was used to adsorb and remove Cd from the solution. 2+ During the removal process, PYRX-aga can show good fluorescence / colorimetric effect, and the removal efficiency can reach more than 96%. Therefore, PYRX is very effective in detecting and removing Cd in actual samples. 2+ It has great application potential.

[0020] The fluorescent probe of the present invention has the characteristics of simple synthesis route, rapid response and little interference from the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is the hydrogen spectrum of the probe PYRX in deuterated DMSO of the present invention, with the abscissa representing chemical shift (ppm) and the ordinate representing intensity.

[0022] Figure 2 In the carbon spectrum of the probe PYRX in deuterated DMSO of the present invention, the abscissa is the chemical shift (ppm) and the ordinate is the intensity.

[0023] Figure 3 The mass spectrometer of the probe PYRX in the invention, the ionization source is: ESI + .

[0024] Figure 4 Time scan of the probe PYRX of the present invention in 5% DMSO.

[0025] Figure 5 The probe PYRX (1×10 -5 mol / L), in 5% DMSO solution, at room temperature, respectively with control, Na + ,K + ,Ca 2+ Mg 2+ ,Al 3+ ,Cu 2+ ,Fe 3+ ,Ag + ,Mn 2+ ,Zn 2+ ,Ni + ,Pb 2+ ,Cd 2+ ,Cr 2+ ,Ba 2+ ,Hg 2+ and Fe 2+ Fluorescence spectrum recorded by the reaction. Excitation wavelength: 340nm.

[0026] Figure 6 The probe PYRX of the present invention is reacted with different concentrations of Cd 2+ The fluorescence intensity after the reaction is linearly related.

[0027] Figure 7 PYRX-Cd 2+ Mass spectrum, ionization source: ESI + .

[0028] Figure 8 The application of the probe of the present invention in agarose gel (PYRX-aga) and its fluorescence detection of Cd 2+ .

[0029] Fig. 9 Application of the probe of the present invention in agarose gel (PYRX-aga) and its colorimetric detection of Cd 2+ .

[0030] Table 1 Cd in actual samples 2+ Recovery data.

[0031] Table 2 The probe PYRX-aga of the present invention for Cd 2+ Data removed by adsorption. DETAILED DESCRIPTION

[0032] The present invention is further described below in conjunction with examples and drawings, but the present invention is not limited to the following embodiments.

[0033] Example 1 Synthesis of PYRX fluorescent probe

[0034] The probe PYRX was synthesized from 1-aminopyrene by a one-step reaction. 1-aminopyrene and p-dibenzaldehyde were added to anhydrous ethanol, the reaction solution was heated to reflux, and the reaction was monitored by a plate. After the reaction was complete, the temperature was cooled to room temperature, and the solvent was removed by rotary evaporation to obtain an orange crude product. The crude product was purified by column chromatography using DCM / PE (v / v, 1:1) as the eluent to obtain an orange solid probe PYRX (0.66 g, 67.03%). 1HNMR(DMSO-d6,400M Hz)δ9.34(s,2H),9.10(d,J=7.44Hz,1H),9.02(dd,J=6.48,7.45Hz,2H),8.96(d,J=6.48Hz,1H),8.90( d,J=6.48Hz,1H),8.81(d,J=7.58Hz,1H),8.75(d,J=6.08Hz,2H),8.67(d,J=7.48Hz,1H),8.57(dd,J=7 .12,7.16Hz,2H),8.48(dd,J=6.48,7.48Hz,2H),8.42(d,J=6.48Hz,1H),8.35(d,J=612Hz,2H),8.30(d d,J=6.48,6.34Hz,2H),8.22(dd,J=6.54,6.29Hz,2H),8.11(t,J=6.08Hz,1H),8.04(d,J=6.74Hz,1H). 13 C NMR(DMSO-d6,125M Hz)δ191.41,165.63,146.35,145.03,144.53,143.89,141.73,139.57,137.14,134.36, 131.90,131.80,131.70,130.07,129.26,128.82,128.38,127.96,127.87,127.73,127.0 9,127.00,126.71,125.73,125.63,124.36,123.64,122.56,122.48,122.38,122.36,12 0.97,120.93,119.32,117.89,117.45,117.02,116.60,116.51,116.37.ESI-Mass:calcd for C 40 H 25 N2:532.1939,found[M+H] + at m / z 533.1945.

[0035] Example 2 Selectivity of PYRX fluorescent probe for different metal ions

[0036] The PYRX fluorescent probe in Example 1 was configured as 1×10 -4 mol / L mother solution.

[0037] The following substances NaCl, KCl, CaCl2, MgCl2·6H2O, AlCl3, CuCl2·2H2O, FeCl3·6H2O, AgNO3, MnCl2·4H2O, ZnCl2, NiCl·6H2O, PbCl2, CdCl2·2.5H2O, CrCl3·6H2O, BaCl2·2H2O, FeCl2·4H2O, HgCl2 were prepared into 2.5×10 -3 mol / L mother solution. Take 18 test tubes and add 120μL of the above different metal ion mother solutions in turn. Replace the interfering substance with an equal amount of water, then add 120μL of DMSO. Finally, add 30μL of the probe mother solution and make it up to 3mL with ultrapure water. After each solution is shaken, perform fluorescence detection (Ex = 340nm). Use fluorescence intensity as the ordinate and wavelength as the abscissa. Figure 5 ;Depend on Figure 5 Can find Cd 2+ It can significantly enhance the fluorescence intensity of PYRX, and other metal ions have almost no interference with its fluorescence intensity.

[0038] Example 3 Different concentrations of Cd 2+ The fluorescence intensity of PYRX

[0039] The concentration is 2.5×10 -3 mol / L Cd 2+ The final Cd content is controlled by changing the volume added to the test tube. 2+ concentration, forming 0-8 equivalents of Cd 2+ After the reaction, fluorescence detection (Ex = 340nm) was performed to detect the fluorescence intensity in each system. With the fluorescence intensity as the ordinate, Cd 2+ The concentration of is the horizontal axis to draw a curve and draw a linear relationship. Figure 6 It can be seen that with the increase of Cd 2+ As the concentration of Cd increases, the fluorescence intensity of the probe gradually increases. 2+ When the content reaches 8 equivalents, the fluorescence of the probe is no longer enhanced.

[0040] Example 4 PYRX fluorescent probe for Cd in different water samples 2+ Detection

[0041] Take 3g of rice and place it in a mixture of nitric acid (15mL) and H2O2 (30%, 20mL). Heat the mixture at 95℃ and stir for 3h, then cool it to room temperature, filter and centrifuge it, and take the supernatant for subsequent testing. Tap water and campus lake water are used directly for testing without any treatment. Add different masses of Cd to the actual sample solution. 2+, so that its final concentration in the test solution was 0, 0.50, 2.00, and 6.00 μmol / L, respectively.

[0042] Add 30 μL of PYRX stock solution, 120 μL of DMSO and 120 μL of actual sample solution to 7 test tubes and finally dilute to 3 mL with ultrapure water. Perform fluorescence detection at Ex = 340 nm. Calculate the recovery rate and RSD. With water samples and food samples as the ordinate, Cd 2+ Concentration, recovery rate and RSD are plotted as the horizontal axis in Table 1. The recovery rates are between 96% and 104%, and the RSD is less than 2.79%.

[0043] Table 1 Cd in actual samples 2+ Recovery data

[0044]

[0045] Table 1 Cd in actual samples 2+ Recovery rate data (continued)

[0046]

[0047] Example 5 PYRX detection of Cd 2+ Application on agarose and its detection of Cd 2+ data.

[0048] Take 2g of agarose and pour it into ultrapure water. Heat it until the agarose is completely dissolved and the solution is clear, then turn off the heat. Then add 600μL of probe stock solution and 2.40mL of DMSO and continue stirring. After stirring evenly, quickly pour it into a beaker and cool it to room temperature to obtain PYRX-aga agarose gel.

[0049] Different concentrations of Cd 2+ Add dropwise onto the surface of PYRX-aga, and after the reaction is complete, take fluorescence / colorimetric photos with a camera under a handheld UV lamp / sunlight.

[0050] Example 6 Removal of Cd by adsorption using agarose gel (PYRX-aga) 2+ Data

[0051] Agarose gel (PYRX-aga) was placed on different concentrations (0.01, 0.10, 1.00, 10, 50, 100 μmol / L) of Cd 2+ The solution was stirred with a stirrer. After the reaction was complete, it was removed. The ICP-MS method was used to determine the Cd content in the solution before and after removal. 2+ The concentration change of Cd 2+ The vertical axis shows the high and low concentrations of Cd 2+The removal rate is plotted as the horizontal axis in Table 2. 2+ The removal rate is above 96%. Even high concentrations of Cd 2+ , the removal rate of PYRX-aga can still reach more than 50%.

[0052] Table 2 Removal of Cd by adsorption by agarose gel (PYRX-aga) 2+ data

[0053]

Claims

1. A gel bispyrene-based fluorescent probe, characterized in that: The structural formula is as follows:

2. The method for preparing the gel bispyrene-based fluorescent probe according to claim 1, characterized in that: The following steps are involved: 1-aminopyrene and p-dibenzaldehyde are uniformly mixed in anhydrous ethanol, the reaction solution is heated to form reflux, the reaction is monitored by a spot plate, the temperature is cooled after the reaction is complete, the solvent is removed by rotary evaporation, and a gel bispyrene-based fluorescent probe is obtained by column chromatography.

3. The preparation method according to claim 2, characterized in that: The molar ratio of 1-aminopyrene to p-dibenzaldehyde is 1.5-2.5:

1.

4. The preparation method according to claim 2, characterized in that: The reaction solution was heated to reflux.

5. The preparation method according to claim 2, characterized in that: The silica gel used in the column chromatography analysis method is 200-300 mesh, and the eluent is: V 二氯甲烷 / V 石油醚 =1 / 1.

6. The gel bispyrene-based fluorescent probe according to claim 1 is used for qualitative and quantitative detection of Cd 2+ Application in.

7. The use according to claim 6, characterized in that: Specifically include: The gel bispyrene-based fluorescent probe PYRX was dissolved in DMSO solvent and prepared into (0.5~2)×10 -4 mol / L probe solution, and then add Cd 2+ After the reaction, the fluorescence change is observed by fluorescence detection at 340nm.

8. The use according to claim 7, characterized in that: Specifically include: The gel bispyrene-based fluorescent probe PYRX was dissolved in DMSO solvent to prepare a fluorescent probe PYRX concentration of 1.0×10 - 6 mol / L solution, and then add Cd 2+ The fluorescence intensity of the sample to be tested is detected, and the Cd is quantitatively calculated based on the linear relationship between the fluorescence intensity and the concentration of the sample to be tested. 2+ The content.

9. The gel bispyrene-based fluorescent probe according to claim 1 is used for preparing agarose gel for quantitative detection of Cd 2+ The application is characterized in that The following steps are involved: Pour agarose into water, heat until agarose is completely dissolved and the solution is clear, then turn off the heat, add the gel bipyrene-based fluorescent probe PYRX and DMSO solvent and continue stirring, and quickly pour into a container after stirring evenly, and cool to obtain PYRX-aga agarose gel; Different concentrations of Cd 2+ Add it dropwise to PYRX-aga agarose gel, wait for the reaction to be complete, and then take fluorescence / colorimetric photos with a camera under a handheld UV lamp / sunlight.

10. The gel bispyrene-based fluorescent probe according to claim 1 is used to prepare agarose gel for adsorption and removal of Cd 2+ The application is characterized in that The following steps are involved: Pour agarose into water, heat until the agarose is completely dissolved and the solution is clear, then turn off the heat, add the gel bipyrene-based fluorescent probe PYRX and DMSO solvent and continue stirring, and quickly pour into a container after stirring evenly, and cool to obtain PYRX-aga agarose gel; PYRX-aga agarose gel was placed on different concentrations of Cd 2+ Stir the solution and after the reaction is complete, add Cd 2+ Remove.

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