CN102504802A - Metallic organic luminescent molecule and hydrotalcite compounded electrochemiluminiscent ultrathin film and method of preparing same - Google Patents

Abstract

The invention discloses an electrochemiluminescence ultrathin film composed of terpyridyl ruthenium (II) chloride and hydrotalcite and a preparation method thereof, which belong to the technical field of preparation of composite luminescent materials. The advantage of the present invention is that the rigid structure of the hydrotalcite laminate and the confinement of the two-dimensional space realize the immobilization of the photoactive complexes and the orderly arrangement on the molecular scale, reducing the occurrence of intermolecular aggregation. Red shift and fluorescence quenching, while simplifying the experimental device of electrochemiluminescence analysis and reducing the loss of solvent. The film preparation process is easy to operate, and the luminous intensity and film thickness of the film can be precisely controlled by changing the assembly times.

Description

A composite electrochemiluminescence ultra-thin film of metal-organic light-emitting molecules and hydrotalcite and its preparation method

Field

The invention belongs to the technical field of preparation of composite luminescent materials, in particular to an electrochemiluminescent ultra-thin film composed of terpyridine ruthenium (II) chloride and hydrotalcite and a preparation method thereof.

Background technique

Double metal composite hydroxide, also known as Layered Double Hydroxides (LDHs for short), is a new type of multifunctional layered material with good chemical stability and strong heat resistance, and LDHs layered metal The type and ratio of ions can be adjusted, and the interlayer anions are exchangeable. This unique crystal structure and physical and chemical properties make it widely used in ion exchange, adsorption, catalysis, polymer modification, optical materials, magnetic materials, electrical materials and many other fields. The hydrotalcite material can be exfoliated into highly dispersed single-layer nanosheets by mechanical stirring in an organic solvent, and then taking into account electrostatic forces, hydrogen bonds, hydrophilic and hydrophobic forces, the exfoliated laminates can be aggregated with different functional properties The material anions are assembled into ordered thin film materials by layer-by-layer self-assembly method.

Electrochemiluminescence (ECL) has high sensitivity, good reproducibility, continuous measurement, simple operation and easy control. Especially in biochemical analysis. Drug analysis and immune analysis are unique. Electrochemiluminescence is a phenomenon in which luminescence is generated through an electrochemical excitation reaction, and it is the product of the combination of CL method and electrochemical method. Therefore, in addition to the advantages of high sensitivity, wide linear range and simple instrument of CL analysis method, ECL analysis method also has many advantages of electrochemical method: (1) The redox state of substances can be easily changed by using electrochemical method. ability, can choose more stable reagents, facilitate the recycling of electrochemically reversible substances, and facilitate the realization of chemiluminescence analysis that requires the participation of extremely unstable reagents; (2) Since the luminescence is excited by electrochemical, it is convenient to adjust the time of luminescence and space; (3) It can provide current signals at the same time, which is convenient for the study of luminescent mechanism.

In the study of electrochemiluminescence, in order to expand the application field of electrochemiluminescence, the reagents that directly or indirectly participate in the chemiluminescent reaction are immobilized on the electrode by chemical modification. Since the electrochemiluminescence sensor reduces the use of expensive reagents to a certain extent and simplifies or miniaturizes the experimental device, it has been paid more and more attention in recent years. Based on this, the electrochemiluminescent composite material with excellent luminescent performance can be obtained by introducing the electrochemiluminescence molecule ruthenium terpyridine molecule into the interlayer of hydrotalcite. At present, there are no literature and patent reports about the combination of hydrotalcite layered materials and ruthenium terpyridyl molecules at home and abroad.

Contents of the invention

The object of the present invention is to provide an electrochemiluminescent ultra-thin film composed of metal organic luminescent molecule terpyridine chloride ruthenium (II) and hydrotalcite and a preparation method thereof. Tripyridine ruthenium(II) chloride is tris(2,2-bipyridine) ruthenium(II) chloride complex. In the present invention, the metal-organic luminescent molecule ruthenium terpyridyl molecule is introduced into the interlayer of hydrotalcite, combined with the confinement effect of the LDHs laminates, the ruthenium terpyridine molecule is uniformly dispersed, and the orientation is single, so as to achieve the single-molecule luminescent effect, thereby obtaining a luminescent compound with excellent luminescent performance. Electrochemiluminescent composite materials. The invention applies hydrotalcite as a novel material in the assembly of electrochemiluminescent molecules, and provides a solution for the uniform dispersion of electrochemiluminescent molecules on the molecular scale.

The technical scheme of the present invention is to assemble the metal-organic light-emitting molecule terpyridyl ruthenium(II) chloride and the hydrotalcite nanosheets peeled off in an organic solvent layer by layer to form a structurally ordered terpyridine ruthenium(II) chloride/hydrotalcite Supramolecular layered material, the composite material makes full use of the rigid structure of hydrotalcite, the confinement effect of two-dimensional space and the interaction between host and guest, and realizes the immobilization of electrochemiluminescent molecules.

The electrochemiluminescence ultra-thin film composited with metal organic light-emitting molecules and hydrotalcite prepared in the present invention is an electrochemiluminescence thin film, which is composed of sodium polystyrene sulfonate, ruthenium (II) chloride terpyridine, and sodium polystyrene sulfonate in sequence. The three-layer guest layer and the inorganic component hydrotalcite nanosheets are assembled alternately in three-dimensional space, which has the characteristics of a layered structure. At the same time, according to the number of assembled layers, the thickness of the film can be uniformly adjusted from several nanometers to hundreds of nanometers; polyphenylene The molecular weight of sodium ethylene sulfonate is 50000-80000.

Concrete preparation method of the present invention is:

1) Preparation of carbonate hydrotalcite precursor:

a. prepare the mixed salt solution of soluble divalent cobalt nitrate and soluble trivalent aluminum nitrate, the concentration of cobalt ion is 0.01-2.00mol/L, and the molar ratio scope of cobalt ion and aluminum ion is 2-3;

b. preparation concentration is the urea solution of 0.01-0.05mol/L, wherein the molar ratio of urea and cobalt ion is 0.5-2;

c. transfer the mixed salt solution prepared in step a into a three-necked bottle, and slowly add the urea solution prepared in step b; Stirring at 95-105°C for 30-60 hours; centrifuging and washing with deionized water until neutral, drying at 20-100°C for 12-24 hours to obtain carbonate-intercalated cobalt-aluminum hydrotalcite;

2) Preparation of nitrate hydrotalcite precursor:

1) the cobalt-aluminum hydrotalcite of the carbonate radical intercalation that 1g step 1) prepares is dispersed in the deionized water that removes CO of _500-2000mL ;

II) Add sodium nitrate and 0.1-0.3mL concentrated nitric acid to step I), the mass ratio of sodium nitrate to carbonate-intercalated cobalt-aluminum hydrotalcite is 100:1-500:1, carry out ion exchange at normal temperature under the protection of inert gas React for 12-24 hours; Centrifuge and wash with deionized water to neutralize _CO2 , and dry at 50-70°C for 12-24 hours to obtain nitrate-intercalated cobalt-aluminum hydrotalcite;

3) Take 0.1 g of nitrate-intercalated cobalt-aluminum hydrotalcite and strip it in 50-200 ml of formamide solvent for 30-60 hours, under nitrogen protection, with a stirring speed of 3000-5000 rpm; the stripped hydrotalcite The solution was centrifuged, and the precipitate was discarded to obtain a clear and transparent colloidal solution B;

4) Prepare 0.5-2 mg/mL sodium polystyrene sulfonate solution C, the molecular weight of sodium polystyrene sulfonate is 50000-80000;

5) Configure 0.0001-0.0005mol/L terpyridine ruthenium(II) chloride solution D;

6) Soak the hydrophilized indium tin oxide transparent conductive film glass in solution B for 10-20 minutes, fully wash it with deionized water, place it in solution C, soak it for 10-20 minutes and wash it again with deionized water , and then placed in solution D, soaked for 10-20 minutes and then cleaned, and finally placed in solution C and soaked for 10-20 minutes and then fully cleaned to obtain a cycle of terpyridyl ruthenium(II) chloride and hydrotalcite composite electrochemiluminescence ultra-thin film;

7) Repeat step 6) for 1-30 times to obtain a composite electrochemiluminescence ultrathin film of terpyridyl ruthenium(II) chloride and hydrotalcite assembled in multiple cycles.

The hydrophilization treatment method in step 6) is: ultrasonically sonicate the indium tin oxide transparent conductive film glass in acetone, ethanol, and deionized water for 10-20 minutes in sequence, and then fully wash with deionized water until pH=7.

The advantage of the present invention is that the immobilization of the photoactive complexes and the orderly arrangement on the molecular scale are realized by utilizing the rigid structure of the hydrotalcite laminate and the confinement effect of the two-dimensional space, which reduces the occurrence of intermolecular aggregation. Red shift and fluorescence quenching, while simplifying the experimental device of electrochemiluminescence analysis and reducing the loss of solvent. The film preparation process is easy to operate, and the luminous intensity and film thickness of the film can be precisely controlled by changing the assembly times.

Description of drawings

Fig. 1 is the ultraviolet absorption spectrogram of the 2-14 cycle assembly terpyridyl ruthenium chloride (II) and hydrotalcite composite electrochemiluminescent ultra-thin film that the embodiment of the present invention 1 obtains, in the figure, it is assembled every 2 cycles A UV spectrum test.

Figure 2 shows the variation of the absorbance at 291 and 457 nanometers in Figure 1 as the number of cyclic assemblies increases.

Fig. 3 is the electrochemiluminescence diagram of the composite electrochemiluminescence ultra-thin film of terpyridyl ruthenium(II) chloride and hydrotalcite assembled in Example 2 of the present invention after 14 cycles.

Detailed ways

Example 1

1. Preparation of carbonate hydrotalcite precursor by urea method:

Step A: 2.91 g (0.01 mol) of solid Co(NO ₃ ) ₂ 6H ₂ O and 1.9 g (0.005 mol) of solid Al(NO ₃ ) ₃ 9H ₂ O were dissolved in 500 mL of deionized water (solution I);

Step B: Dissolve 3 g (0.009 mol) of urea in 500 mL of deionized water (solution II);

Step C: Put the solution I prepared in step A in a four-necked flask, and while vigorously stirring, slowly add solution II to solution I dropwise, about 0.5h after the drop, and then use an ammonia solution with a concentration of 20% by mass Adjust the pH to 8, react in an oil bath at 95°C for 48 hours, centrifugally wash with deionized water until neutral, and dry at 70°C for 24 hours to obtain carbonate-intercalated cobalt-aluminum hydrotalcite;

2. Preparation of nitrate hydrotalcite precursor by acid exchange method:

Weigh 1g of carbonate intercalated cobalt aluminum hydrotalcite prepared in step 1 and 127.5g of solid NaNO ₃ and dissolve it in 1000mL of deionized water with CO ₂ removed. After uniform dispersion, add 0.225mL of concentrated nitric acid, stir under nitrogen atmosphere, and After ion exchange reaction for 24 hours, centrifuge washing with CO ₂ deionized water until neutral, and dry at 70°C for 12 hours to obtain cobalt-aluminum hydrotalcite intercalated with nitrate radicals;

3. Take 0.1 g of the cobalt-aluminum hydrotalcite intercalated with the above-mentioned nitrate radicals, stir in 100 milliliters of formamide solvent for 48 hours under nitrogen atmosphere conditions, and the stirring speed is 4000 rpm, centrifuge the hydrotalcite solution after stripping, discard Remove the precipitate to obtain a clear and transparent colloidal solution B;

4. Prepare 1mg/mL sodium polystyrene sulfonate solution C, the molecular weight of sodium polystyrene sulfonate is 60000;

5. Configure terpyridine ruthenium (II) chloride solution D of 0.0003mol/L;

6. Sonicate the indium tin oxide transparent conductive film glass in acetone, ethanol, and deionized water for 15 minutes in sequence, and then fully wash it with deionized water until pH = 7, then place it in solution C, soak it for 15 minutes, and wash it again with deionized water. Place in solution D afterwards, wash after soaking for 15 minutes, and finally place in solution C and soak for 15 minutes and then fully wash to obtain a cycle of terpyridyl ruthenium(II) chloride and hydrotalcite composite electrochemiluminescence ultra-thin film;

7. Repeat steps 6 and 25 times to obtain a composite electrochemiluminescent ultrathin film of terpyridyl ruthenium(II) chloride and hydrotalcite assembled in multiple cycles.

Characterization of terpyridine ruthenium(II) chloride and hydrotalcite composite electrochemiluminescent ultrathin films: As can be seen from Figure 1, terpyridine ruthenium(II) chloride and hydrotalcite composite electrochemiluminescence ultrathin films increase with the number of cycle assembly , the maximum absorption peak of its ultraviolet absorption spectrum presents a growing trend, as shown in Figure 2, the absorbance is close to a linear relationship with the number of cyclic assemblies, indicating that the amount of terpyridyl ruthenium chloride (II) assembled each time is a fixed value.

Example 2

1. With embodiment 1;

2. With embodiment 1;

3. With embodiment 1, obtain clear transparent colloidal solution B;

4. Prepare 1mg/mL sodium polystyrene sulfonate solution C, the molecular weight of sodium polystyrene sulfonate is 70000;

5. Configure terpyridine ruthenium(II) chloride solution D of 0.0001mol/L;

6. Sonicate the indium tin oxide transparent conductive film glass in acetone, ethanol, and deionized water for 10 minutes, then wash it with deionized water until pH = 7, then soak it in solution B for 10 minutes, rinse with deionized water After fully cleaning, place it in solution C, soak for 10 minutes and wash it again with deionized water, then place it in solution D, soak it for 10 minutes and wash it, and finally place it in solution C for 10 minutes and wash it thoroughly to obtain a cycle of triple Pyridine ruthenium(II) chloride and hydrotalcite composite electrochemiluminescence ultra-thin film;

7. Repeat steps 6 and 14 times to obtain a composite electrochemiluminescence ultrathin film of terpyridyl ruthenium(II) chloride and hydrotalcite assembled in multiple cycles.

Use the electrochemical workstation to use silver/silver chloride as the reference electrode, platinum wire as the counter electrode, and the terpyridyl ruthenium(II) chloride and hydrotalcite composite electrochemiluminescent ultra-thin film assembled in step 7 for 14 cycles as the working electrode , using 0.1 mole/liter of phosphate buffer solution as electrolyte, and performing cyclic voltammetry scanning in the range of 0.5-1.2 volts. It can be seen from the electrochemiluminescence diagram of Figure 3 that terpyridyl ruthenium(II) chloride is compounded with hydrotalcite The electrochemiluminescence ultrathin films obtained stable electrochemiluminescence signals.

Example 3

1. With embodiment 1;

2. With embodiment 1;

3. With embodiment 1, obtain clear transparent colloidal solution B;

4. Prepare 1mg/mL sodium polystyrene sulfonate solution C, the molecular weight of sodium polystyrene sulfonate is 80000;

5. Configure terpyridine ruthenium (II) chloride solution D of 0.0005mol/L;

6. Sonicate the indium tin oxide transparent conductive film glass in acetone, ethanol, and deionized water for 20 minutes in sequence, then fully wash it with deionized water until pH = 7, then soak it in solution B for 20 minutes, rinse with deionized water After fully cleaning, place it in solution C, soak for 20 minutes and wash it again with deionized water, then place it in solution D, soak it for 20 minutes and then wash it, and finally place it in solution C for 20 minutes and wash it thoroughly to obtain a cycle of triple Pyridine ruthenium(II) chloride and hydrotalcite composite electrochemiluminescence ultra-thin film;

7. Repeat steps 6 and 20 times to obtain a composite electrochemiluminescence ultrathin film of terpyridyl ruthenium (II) chloride and hydrotalcite assembled in multiple cycles.

Claims (3)

1. a metal organic luminescent molecule and hydrotalcite composite electrochemiluminescent ultra-thin film, it is characterized in that: described ultra-thin film is electrochemiluminescent thin film, and it is made of sodium polystyrene sulfonate, terpyridyl ruthenium chloride (II), The three-layer guest layer composed of sodium polystyrene sulfonate and the inorganic component hydrotalcite nanosheets are assembled alternately in three-dimensional space, which has the characteristics of a layered structure. Uniform control between hundreds of nanometers; the molecular weight of sodium polystyrene sulfonate is 50,000-80,000. 2. A composite electrochemiluminescent ultra-thin film of metal organic light-emitting molecules and hydrotalcite and a preparation method thereof, characterized in that the specific operation steps are as follows: 1) Preparation of carbonate hydrotalcite precursor: a. prepare the mixed salt solution of soluble divalent cobalt nitrate and soluble trivalent aluminum nitrate, the concentration of cobalt ion is 0.01-2.00mol/L, and the molar ratio scope of cobalt ion and aluminum ion is 2-3; b. preparation concentration is the urea solution of 0.01-0.05mol/L, wherein the molar ratio of urea and cobalt ion is 0.5-2; c. transfer the mixed salt solution prepared in step a into a three-necked bottle, and slowly add the urea solution prepared in step b; Stirring at 95-105°C for 30-60 hours; centrifuging and washing with deionized water until neutral, drying at 20-100°C for 12-24 hours to obtain carbonate-intercalated cobalt-aluminum hydrotalcite; 2) Preparation of nitrate hydrotalcite precursor: 1) the cobalt-aluminum hydrotalcite of the carbonate radical intercalation that 1g step 1) prepares is dispersed in the deionized water that removes CO of _500-2000mL ; II) Add sodium nitrate and 0.1-0.3mL concentrated nitric acid to step I), the mass ratio of sodium nitrate to carbonate-intercalated cobalt-aluminum hydrotalcite is 100:1-500:1, carry out ion exchange at normal temperature under the protection of inert gas React for 12-24 hours; Centrifuge and wash with deionized water to neutralize _CO2 , and dry at 50-70°C for 12-24 hours to obtain nitrate-intercalated cobalt-aluminum hydrotalcite; 3) Take 0.1 g of nitrate-intercalated cobalt-aluminum hydrotalcite and strip it in 50-200 ml of formamide solvent for 30-60 hours, under nitrogen protection, with a stirring speed of 3000-5000 rpm; the stripped hydrotalcite The solution was centrifuged, and the precipitate was discarded to obtain a clear and transparent colloidal solution B; 4) Prepare 0.5-2 mg/mL sodium polystyrene sulfonate solution C, the molecular weight of sodium polystyrene sulfonate is 50000-80000; 5) Configure 0.0001-0.0005mol/L terpyridine ruthenium(II) chloride solution D; 6) Soak the hydrophilized indium tin oxide transparent conductive film glass in solution B for 10-20 minutes, fully wash it with deionized water, place it in solution C, soak it for 10-20 minutes and wash it again with deionized water , and then placed in solution D, soaked for 10-20 minutes and then cleaned, and finally placed in solution C and soaked for 10-20 minutes and then fully cleaned to obtain a cycle of terpyridyl ruthenium(II) chloride and hydrotalcite composite electrochemiluminescence ultra-thin film; 7) Repeat step 6) for 1-30 times to obtain a composite electrochemiluminescence ultrathin film of terpyridyl ruthenium(II) chloride and hydrotalcite assembled in multiple cycles. 3. The preparation method according to claim 2, characterized in that, the hydrophilization treatment method described in step 6) is: the indium tin oxide transparent conductive film glass is successively ultrasonicated in acetone, ethanol, and deionized water for 10- 20 minutes, and then fully washed with deionized water to pH=7.

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