CN113372902A

CN113372902A - DNA composite gel for optical information storage and preparation method thereof

Info

Publication number: CN113372902A
Application number: CN202110633163.3A
Authority: CN
Inventors: 刘凯; 张洪杰
Original assignee: Tsinghua University
Current assignee: Tsinghua University
Priority date: 2021-06-07
Filing date: 2021-06-07
Publication date: 2021-09-10
Anticipated expiration: 2041-06-07
Also published as: CN113372902B

Abstract

The invention relates to the technical field of material preparation, in particular to a DNA composite gel for optical information storage and a preparation method thereof. The rare earth DNA composite gel is prepared from a nucleic acid solution, a terpyridine cation derivative aqueous solution and rare earth chloride. Experiments show that the rare earth DNA composite gel can be used for optical information storage of a flexible substrate, has good plasticity, machinability and high mechanical property, can be used for processing various macroscopic materials in different forms, can be used for coding by taking fluorescence of the rare earth DNA composite organogel as a coding element, can finish the encryption writing and storage of information, can effectively store the information on the flexible substrate, and opens up a way for the application of rare earth luminescence in information flexibility. The preparation method has simple process and high operability.

Description

DNA composite gel for optical information storage and preparation method thereof

Technical Field

The invention relates to the technical field of material preparation, in particular to a DNA composite gel for optical information storage and a preparation method thereof.

Background

With the explosive development of information technology, a large amount of invalid information fills our lives, and people pay more and more attention to the information protection work. The information coding and information storage are carried out by utilizing the light, so that the information safety can be effectively guaranteed, and the development prospect is wide. At present, the optical information storage material is mainly concentrated on a hard material substrate, and the flexible and processable optical information storage material needs to be further researched, so that the further development of the flexible optical information storage device is limited. Therefore, the search for macroscopic materials with flexibility and processability to achieve data encoding and decoding applications remains an urgent problem to be solved.

The rare earth material has unique optical characteristics and is widely applied to the aspects of information storage and anti-counterfeiting in recent years. Compared with luminescent materials such as organic micromolecules, perovskite, quantum dots and the like, the rare earth material has unique optical characteristics such as multiple excitation wavelengths, multicolor emission, long fluorescence life and the like, and the optical characteristics expand the application of the rare earth material in the fields of optical storage, encryption, anti-counterfeiting and the like. However, optical information storage using rare earths often relies on nanomaterials and an external carrier, and the information carried is usually fixed and difficult to re-edit and modify. Therefore, optimizing rare earth materials to produce a flexible and processable rare earth optical information storage material remains a challenge.

The fluorescent hydrogel and the multi-dimensional information storage system and method disclosed in publication number CN110903495A are prepared by mixing a fluorescent monomer with acrylamide, acrylic acid, an initiator and a cross-linking agent to prepare a pre-polymerization solution, and performing a polymerization reaction on the pre-polymerization solution to prepare the fluorescent hydrogel capable of storing information. Patterned storage of information is achieved by forming a printed pattern on the fluorescent hydrogel using a dye printing agent. However, the method has complicated operation steps, and the influence of the flexibility and deformation effect of the material on information is not involved, so that the application and the expansion of the gel material on a flexible substrate are limited to a certain extent.

Disclosure of Invention

In order to overcome the problems that optical information storage materials in the prior art are low in flexibility and processability, are limited in application in the using process and low in mechanical strength of the conventional rare earth organogel materials, the invention provides the rare earth DNA composite organogel for optical information storage and the preparation method and application thereof.

In order to achieve the above object, the present invention provides the following technical solutions:

the invention provides a preparation method of rare earth DNA composite gel, which comprises the following steps:

mixing the nucleic acid solution, the terpyridine cation derivative aqueous solution and the rare earth chloride aqueous solution, and immediately performing vortex oscillation to obtain a mixed solution;

and centrifuging and freeze-drying the mixed solution, and adding an organic solvent for swelling to obtain the rare earth DNA composite organogel.

The DNA composite gel prepared from the nucleic acid solution, the terpyridine cation derivative aqueous solution and the rare earth chloride can be used for optical information storage of a flexible substrate, and has good plasticity, processability and high mechanical property.

The rare earth material has unique optical characteristics, such as multiple excitation wavelengths, multicolor emission, long fluorescence life and the like, and is widely applied to the fields of optical storage, encryption, anti-counterfeiting and the like. The rare earth material is combined with the stretchable flexible material, so that the fluorescence characteristic of the original rare earth material can be maintained, and meanwhile, the stretchable flexible material is endowed with the characteristic of flexibility and processability and can be used for further information encoding.

The DNA macromolecule chain has stable complementary pairing base, the mutual stacking interaction between the bases enhances the strength of the DNA molecule chain, and in addition, the large number of phosphoric acid functional groups also provides sites for reaction with other substances, so that the material is an ideal choice for preparing the stretchable flexible material.

According to the invention, DNA macromolecules are matched with the terpyridine cation derivatives by further utilizing the coulomb effect, so that the interaction between DNA molecular chains is improved. In addition, the interaction of the whole complex network system is further enhanced by introducing rare earth elements and terpyridine cation derivatives for coordination, and the fluorescence characteristic of rare earth is introduced into the whole complex system, so that the rare earth DNA composite organogel with high mechanical strength is prepared.

In some embodiments, the volume ratio of the nucleic acid solution, the terpyridine cation derivative aqueous solution, and the rare earth chloride aqueous solution is 1: (0.01-0.15). In some embodiments, the ratio may be 1:1:0.05, 1:1:0.12, 1:1: 0.1.

In some embodiments, the concentration of the nucleic acid solution is 2-20 mg/ml, and in some embodiments may be 10mg/ml or 15 mg/ml.

In the present invention, the nucleic acid solution is an aqueous nucleic acid solution. Wherein, the nucleic acid is preferably double-stranded DNA, the molecular weight is preferably 10-1000 ten thousand Da, and the nucleic acid can be obtained in the market or extracted by a conventional method. In a specific embodiment of the invention, the nucleic acid is salmon sperm DNA, which is commercially available.

In some embodiments, the concentration of the terpyridine cation derivative aqueous solution is 2-20 mg/ml, and in some embodiments, the concentration may be 10mg/ml or 15 mg/ml. Wherein, the terpyridine dication derivative is a long chain section with one end provided with a terpyridine group and the other end provided with dication; in some embodiments, the terpyridine cation derivative is 1,1' - (((5- ([2,2':6', 2' -terpyridine ] -4' -yl) -1, 3-phenylene) bis (oxy)) bis (hexane-6, 1-diyl)) bis (3-methyl-1H-imidazol-3-ium), which has the structure shown in FIG. 1 and is synthesized by the following steps:

3, 5-dimethoxybenzaldehyde (3.32g,20mmol) and 2-acetylpyridine (4.84g,40mmol) were put into a 250mL flask and dissolved with 100mL of absolute ethanol under stirring. Ground KOH (3.08g, 35mmol) was added and the reaction was carried out at room temperature for 12 hours. 60mL of 25% aqueous ammonia was added to the mixture, and the mixture was heated to 60 ℃ to react for 24 hours. And (4) carrying out suction filtration, washing a filter cake by using absolute ethyl alcohol, drying and carrying out silica gel column chromatography to obtain an intermediate 1.

Intermediate 1(3.69g,10mmol) was dissolved in 80mL hydrobromic acid (40%), oil at 130 ℃ overnight, HBr was removed by rotary evaporation, the resulting yellow solid was washed with saturated sodium bicarbonate, the precipitate turned purple, filtered with suction, and dried to give intermediate 2.

1, 6-dibromohexane (12.1g,50mmol) and 2g potassium carbonate were dissolved in 100mL acetonitrile and heated to 70 ℃. Intermediate 2(1.7g,5mmol) was dissolved in 20mL acetonitrile and slowly added dropwise to the flask and reacted for 24 h. After the reaction was completed, the mixture was filtered. The filtrate is evaporated by rotation, and the intermediate 3 is obtained by silica gel column chromatography.

1 methylimidazole (0.82g,10mmol) and intermediate 3(1g,1.5mmol) were dissolved in 100mL acetonitrile and refluxed at 80 ℃ for 24 hours. Cooling to room temperature, rotary evaporating, dissolving with small amount of water, and precipitating with large amount of ethyl acetate. The resulting crystals were dissolved in water and lyophilized to give compound 4, the final product.

In some embodiments, the concentration of the aqueous rare earth chloride solution is 0.005 to 0.015 mol/ml. In some embodiments, red, the concentration of the aqueous rare earth chloride solution is 0.01 mol/ml.

Wherein the rare earth chloride is at least one of europium trichloride, terbium trichloride, lanthanum trichloride, cerium trichloride, dysprosium trichloride and samarium trichloride. In some embodiments, the rare earth chloride is specifically dysprosium trichloride, europium trichloride, or a mixture of europium trichloride and terbium trichloride.

In the invention, the frequency of vortex oscillation is 1800-3200 r/min, and the time is 2-10 min.

In some embodiments, the centrifugation is at 8000 to 12000rpm for 2 to 5 min; in some embodiments, the centrifugation is at 10000rpm for 2 min.

In the preparation method provided by the invention, the steps of washing the precipitate with water and adding water for vortex oscillation are also included after the centrifugation and before the freeze-drying; the number of times of washing and precipitating is 2-4, the frequency of vortex oscillation is 1800-3200 r/min, and the time is 2-10 min. In some embodiments, the number of washing the precipitate with water is 3, the frequency of vortex oscillation is 2500r/min, and the time is 2 min.

In the present invention, the organic solvent is a polar aprotic solvent; the polar aprotic solvent is one or more of dimethyl sulfoxide, N-dimethylformamide or N-methylpyrrolidone; the swelling time is 24-72 h.

In some embodiments, the preparation method specifically comprises the following steps:

the method comprises the following steps: preparing a salmon sperm DNA aqueous solution with the mass fraction of 2-20 mg/ml, and fully shaking and stirring uniformly;

step two: preparing a terpyridine cation derivative aqueous solution with the mass fraction of 2-20 mg/ml, and fully shaking and stirring uniformly;

step three: preparing 0.01mol/ml rare earth trichloride aqueous solution, fully shaking and stirring uniformly;

step four: and (3) respectively taking 1ml of the solution obtained in the first step and the solution obtained in the second step, mixing the solution with the same volume, and simultaneously adding 10-150 mu L of the liquid prepared in the third step. Mixing the above liquids, and immediately performing vortex oscillation for 2 min;

step five: centrifuging the mixed liquid in the fourth step for 2min at 10000rpm, adding 1ml of distilled water into the centrifuged precipitate, and performing vortex oscillation for 2 min;

step six: repeating the step five twice, and fully washing the precipitate obtained in the step five with water;

step seven: putting the precipitate obtained in the sixth step into liquid nitrogen for freezing, and simultaneously putting the precipitate into a freeze dryer for freeze-drying treatment;

step eight: and (3) placing the freeze-dried product obtained in the step seven into a dimethyl sulfoxide solution to be soaked (i.e. swelled) for 12-72 h, and uniformly mixing after soaking to obtain the rare earth DNA composite organic gel for optical information storage.

The invention also provides the rare earth DNA composite gel prepared by the preparation method.

According to the invention, by reasonably controlling the doped rare earth elements and the content of the rare earth elements, the fluorescence characteristic of the prepared rare earth DNA composite organogel can be regulated and controlled, so that the rare earth DNA composite organogel can emit fluorescence with a specific wavelength under 405nm ultraviolet light. The rare earth DNA composite organogel has fluorescence characteristic and plasticity, can be used for processing various macroscopic materials with different forms, can effectively store information on a flexible substrate due to the plasticity and the processability of the material, and opens up a way for the application of rare earth luminescence in information flexibility. In addition, the fluorescence of the rare earth DNA composite organic gel is used as a coding element for coding, and the information can be written and stored in an encrypted manner. Meanwhile, the method has the advantages of simple process, convenient preparation and high operability.

Drawings

FIG. 1 is a chemical structure diagram of a terpyridine cation derivative of the present invention;

FIG. 2 shows the tensile mechanical properties of the organogel prepared in example 1;

FIG. 3 is a rare earth organogel fluorescent two-dimensional code pattern prepared in example 2;

FIG. 4 is a fluorescent encoding pattern of rare earth organogel prepared in example 3;

FIG. 5 is a fluorescent encoding pattern of rare earth organogel after stretching prepared in example 3;

FIG. 6 is a fluorescent encoding pattern of the rare earth organogel after bending prepared by example 3.

Detailed Description

The invention provides a rare earth DNA composite gel and a preparation method thereof. Those skilled in the art can modify the process parameters appropriately to achieve the desired results with reference to the disclosure herein. It is expressly intended that all such similar substitutes and modifications which would be obvious to one skilled in the art are deemed to be included in the invention. While the methods and applications of this invention have been described in terms of preferred embodiments, it will be apparent to those of ordinary skill in the art that variations and modifications in the methods and applications described herein, as well as other suitable variations and combinations, may be made to implement and use the techniques of this invention without departing from the spirit and scope of the invention.

The test materials adopted by the invention are all common commercial products and can be purchased in the market.

mixing a salmon sperm DNA aqueous solution, a terpyridine cation derivative aqueous solution and a rare earth chloride aqueous solution, and immediately performing vortex oscillation to obtain a mixed solution;

In some embodiments, the preparation method specifically comprises the steps of:

The invention is further illustrated by the following examples:

example 1:

a preparation method of rare earth DNA composite organic gel for optical information storage comprises the following steps:

the method comprises the following steps: preparing salmon sperm DNA aqueous solution with the mass fraction of 15mg/ml, and fully shaking and stirring uniformly;

step two: preparing a terpyridine cation derivative aqueous solution with the mass fraction of 15mg/ml, and fully shaking and stirring uniformly;

step three: preparing a 0.01mol/ml dysprosium trichloride aqueous solution, fully shaking and stirring uniformly;

step four: and (3) respectively taking 1ml of the solution obtained in the first step and the solution obtained in the second step, mixing the solutions in equal volumes, and simultaneously adding 50 mu L of the liquid prepared in the third step. Mixing the above liquids, and immediately performing vortex oscillation for 2 min;

step five: centrifuging the mixed liquid in the fourth step for 2min at 10000rpm, adding 1ml of distilled water into the centrifuged precipitate, and performing vortex oscillation at 2500rpm for 3 min;

step six: repeating the fifth step twice, and fully washing the precipitate obtained in the fourth step with water;

step eight: and (5) placing the freeze-dried product obtained in the step seven into a dimethyl sulfoxide solution to be soaked for 72 hours, and uniformly mixing after soaking.

Step nine: and (3) detecting the mechanical property of the rare earth DNA composite organic gel. The prepared organogel is stretched and then collected by a yarn collecting strand, and the collected organogel yarn is subjected to mechanical property test, which is shown in fig. 2. The result shows that the prepared rare earth DNA composite organogel has strong mechanical property.

Example 2:

step three: preparing 0.01mol/ml europium trichloride aqueous solution, fully shaking and stirring uniformly;

step four: and (3) respectively taking 1ml of the solution obtained in the first step and the solution obtained in the second step, mixing the solutions in equal volumes, and simultaneously adding 120 mu L of the liquid prepared in the third step. Mixing the above liquids, and immediately performing vortex oscillation for 2 min;

step five: centrifuging the mixed liquid in the fourth step for 2min at 10000rpm, adding 1ml of distilled water into the centrifuged precipitate, and performing vortex oscillation at 1800rpm for 5 min;

Step nine: and (3) carrying out fluorescence coding test on the rare earth DNA composite organic gel. And editing the shape of the rare earth DNA organogel through a die to prepare a rare earth organogel two-dimensional code pattern with a certain shape. The prepared gel emits red fluorescence under the irradiation of 405nm ultraviolet light, and meanwhile, the stored information can be collected through mobile phone scanning, as shown in fig. 3.

Example 3:

the method comprises the following steps: preparing salmon sperm DNA aqueous solution with the mass fraction of 10mg/ml, and fully shaking and stirring uniformly;

step two: preparing a terpyridine cation derivative aqueous solution with the mass fraction of 10mg/ml, and fully shaking and stirring uniformly;

step three: respectively preparing 0.01mol/ml europium trichloride and terbium trichloride aqueous solutions, and fully shaking and stirring the aqueous solutions uniformly;

step four: and (3) respectively taking 1ml of the solution obtained in the first step and the solution obtained in the second step, mixing the solutions in equal volumes, and simultaneously adding 100 mu L of the liquid prepared in the third step. Mixing the above liquids, and immediately performing vortex oscillation for 2 min;

step five: centrifuging the mixed liquid in the fourth step for 2min at 10000rpm, adding 1ml of distilled water into the centrifuged precipitate, and performing vortex oscillation at 3200rpm for 2 min;

Step nine: and carrying out fluorescence coding on the rare earth DNA composite organic gel and testing the plasticity and the information retention of the organic gel on the soft bottom material. Respectively cutting the europium-doped rare earth DNA organogel and the terbium-doped rare earth DNA organogel into organogel strips with relatively consistent sizes. The europium-doped rare earth DNA organogel emits red fluorescence under the irradiation of 405nm ultraviolet light, and the terbium-doped rare earth DNA organogel emits green fluorescence under the irradiation of 405nm ultraviolet light. And (3) carrying out information coding by taking the emitted fluorescent color as a storage unit, wherein the red is marked as '0' and the green is marked as '1'. The rare earth organogel was placed on a stretchable soft substrate and data "19" was encoded into the rare earth organogel. When the ultraviolet light is not irradiated, no information can be read, and the stored '19' information can be read under the irradiation of the ultraviolet light with the wavelength of 405nm, as shown in figure 4. In addition, the rare earth DNA composite gel is also deformed when the soft substrate is stretched and bent, but the stored information is not changed, as shown in FIGS. 5 and 6, respectively, the prepared rare earth organic gel can be used for optical information storage of the flexible substrate.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that it is obvious to those skilled in the art that various modifications and improvements can be made without departing from the principle of the present invention, and these modifications and improvements should also be considered as the protection scope of the present invention.

Claims

1. A preparation method of rare earth DNA composite gel is characterized by comprising the following steps:

mixing the nucleic acid aqueous solution, the terpyridine cation derivative aqueous solution and the rare earth chloride aqueous solution, and immediately performing vortex oscillation to obtain a mixed precipitate;

and centrifuging and freeze-drying the mixed precipitate, and adding an organic solvent for swelling to obtain the rare earth DNA composite organogel.

2. The method of claim 1, wherein the volume ratio of the nucleic acid solution, the terpyridine cation derivative aqueous solution, and the rare earth chloride aqueous solution is 1: (0.01-0.15).

3. The method according to claim 1, wherein the concentration of the aqueous nucleic acid solution is 2 to 20 mg/ml.

4. The method of claim 1, wherein the aqueous solution of the terpyridine cation derivative has a concentration of 2 to 20 mg/ml.

5. The method according to claim 1, wherein the concentration of the aqueous rare earth chloride solution is 0.01 mol/ml; the rare earth chloride is at least one of europium trichloride, terbium trichloride, lanthanum trichloride, cerium trichloride, dysprosium trichloride and samarium trichloride.

6. The method according to claim 1, wherein the vortex oscillation frequency is 1800-3200 rpm and the time is 2-10 min.

7. The method according to claim 1, wherein the centrifugation is carried out at 8000 to 12000rpm for 2 to 5 min.

8. The preparation method according to claim 1, further comprising the steps of washing the precipitate with water, adding water, and vortexing after the centrifugation and before the lyophilization; the washing precipitation times are 2-4 times, the vortex oscillation frequency is 1800-3200 rpm, and the time is 2-10 min.

9. The production method according to claim 1, wherein the organic solvent is a polar aprotic solvent; the swelling time is 24-72 h.

10. The rare earth DNA composite gel prepared by the preparation method of any one of claims 1 to 9.