Up-down conversion multi-mode luminescent material and preparation method and application thereof

Abstract

The invention discloses an up-down conversion multi-mode luminescent material and a preparation method and application thereof, and the preparation method comprises the following steps: respectively dispersing a down-conversion material and an up-conversion material in an absolute ethyl alcohol solvent, adding a dispersing agent and a thickening agent, and uniformly dispersing to prepare a uniform and stable luminescent material; the down-conversion material is an Eu < 3 + > complex and / or a Tb < 3 + > complex and / or a Zn < 2 + > complex, and the Eu < 3 + > complex, the Tb < 3 + > complex and the Zn < 2 + > complex are compounded with a polyelectrolyte solution to form the stable polyelectrolyte compounded down-conversion luminescent material; the upconversion material is NaGdF4: Yb, Er nanoparticles, and the NaGdF4: Yb, Er nanoparticles are modified with a water-soluble polymer to form the stable water-soluble NaGdF4: Yb, Er upconversion material. The method has more advantages in the aspects of manufacturing of high-safety anti-counterfeit labels, information storage and detection of harmful heavy metal ions in the environment.

Description

Technical Field

[0001] The present invention relates to the field of optics, functional materials and information security technology, and in particular to an up-down conversion multimodal luminescent material and a preparation method and application thereof. 3+ ,Tb 3+ ,Zn 2+ ) and upconversion nanoparticles (NaGdF4:Yb,Er). The ink achieves orthogonal fluorescence output through dual-mode excitation (UV / NIR), combines reversible metal ion fluorescence quenching response with high-resolution electrohydraulic dynamic (EHD) printing technology, and is suitable for dynamic information hiding, environmental heavy metal detection, and high-density data storage. Background Art

[0002] In the information age, the importance of information security and storage has become increasingly prominent. Traditional information storage and security protection methods face severe challenges. Anti-counterfeiting technology is also difficult to resist forgery and unauthorized access due to single-mode detection and predictable coding strategies. At the same time, environmental sensing technology has insufficient sensitivity and selectivity for heavy metal ion detection, making it impossible to achieve real-time and accurate monitoring.

[0003] Luminescent materials have shown great potential in secure data storage and anti-counterfeiting. Their unique optical properties can realize multi-level data encoding and secure information retrieval, and their ability to respond to specific stimuli can also add interactivity to stored information. Although existing luminescent materials such as organic dyes, inorganic phosphors and semiconductor quantum dots have certain luminescent properties, they cannot simultaneously meet the requirements of multimodal excitation, high-sensitivity sensing and high-precision printing. They have visible traces under natural light and are not suitable for a variety of information storage. Therefore, it is of great practical significance to develop a new material and system that integrates multimodal anti-counterfeiting, efficient information storage and precise environmental sensing. Summary of the invention

[0004] The purpose of the present invention is to provide a new type of luminescent material for multimodal anti-counterfeiting and information storage, and its preparation method and application in view of the deficiencies of the prior art. The luminescent material combines down-conversion and up-conversion luminescent materials to prepare a nanocomposite material with dual-mode fluorescence characteristics. The luminescent material can realize multi-level data encoding and dynamic information hiding under ultraviolet and near-infrared light excitation, realize multi-color luminescent output and orthogonal luminescent characteristics, and has high stability and reversibility. Through electrohydrodynamic (EHD) printing technology, it is not only suitable for information storage and anti-counterfeiting, but also has environmental sensing function and can detect harmful heavy metal ions.

[0005] The technical solution of the present invention is as follows:

[0006] A method for preparing a multimodal up-down conversion luminescent material comprises the following steps: dispersing a down-conversion material and an up-conversion material in an anhydrous ethanol solvent respectively, adding a dispersant and a thickener, and after uniform dispersion, obtaining a uniform and stable luminescent ink; the down-conversion material is: Eu 3+ Complex and / or Tb 3+ Complex and / or Zn 2+ The three down-conversion materials can respectively realize red, green and blue multi-color luminescence under ultraviolet (UV) excitation, with good luminescence efficiency; the three can combine with ligands to form a stable luminescence system, realize multi-color luminescence, and meet a wide range of coding needs. 3+ , Tb 3+ and Zn 2+ The complex is compounded with the polyelectrolyte solution to form a stable polyelectrolyte-complexed down-conversion luminescent material, which enhances its biocompatibility and mechanical stability, and is conducive to the formulation of environmentally friendly inks and the preparation of complex patterns; the up-conversion material is: NaGdF4:Yb, Er nanoparticles, which emit green light under near-infrared light (NIR) excitation, and are modified with water-soluble polymers to form stable water-soluble NaGdF4:Yb, Er up-conversion nanoparticles, which improve their water dispersibility, stability and viscosity, and adapt to the ink system. The luminescence spectra of the down-conversion material and the up-conversion material interact without interference;

[0007] The preparation method, Eu 3+ Complex or Tb 3+ Preparation of complexes; Eu 3+ or Tb 3+ :The stoichiometric ratio of the first organic ligand: the second organic ligand ranges from 1:1:1 to 1:3:1; the first organic ligand is one of 4-mercaptobenzoic acid (4-MBA), p-chlorobenzoic acid (4-CBA), iminooxalic acid (IDA), dibenzoylmethane (DBM), 2-thenoyltrifluoroacetone (TTA), acetylacetone (AcAc), and 1,2-diaminocyclohexane-1,2-diacetic acid (DCTA), and the second organic ligand is one of 2,2-bipyridine (bpy), 2,2-bipyridinedicarboxylic acid (DPA), 8-hydroxyquinoline (8-Hyd), and 1,10-o-phenanthroline (Phen).

[0008] The preparation method, Zn 2+ Preparation of complexes, Zn 2 : The stoichiometric ratio of the organic ligand is in the range of 1:1 to 1:3; the organic ligand is one of ethylenediamine (EN), ethanolamine (MEA), thiourea (TU), and 2-(2-hydroxyphenyl)benzothiazole (BTZ);

[0009] In the preparation method, the polyelectrolyte solution is one of sodium alginate (SA), hyaluronic acid (HA), carboxymethyl cellulose (CMC) and pectin (PGA).

[0010] The preparation method, Eu 3+ / Tb 3+ / Zn 2+ The concentration of the complex: polyelectrolyte solution ranges from 1:1 to 4:1, ensuring that the requirements for subsequent ink preparation are met.

[0011] The preparation method, Eu 3+ Complex or Tb 3+ The preparation method of the complex is as follows: the first organic ligand solution is added dropwise to the EuCl3·6H2O solution or the TbCl3·6H2O solution, stirred at room temperature for 0.5-1 hour by a magnetic stirrer, the pH of the reaction solution is adjusted to 6-8 with dilute ammonia water, and the second organic ligand solution is added thereto, stirred for 1-2 hours, and the EuCl3·6H2O solution is synthesized. 3+ or Tb 3+ Complexes;

[0012] The preparation method, Zn 2+ The preparation method of the complex is as follows: add the organic ligand solution dropwise to the ZnCl2 solution, stir at room temperature for 1-2 hours with a magnetic stirrer, and synthesize Zn 2+ Complex; Prepare Eu 3+ ,Tb 3+ ,Zn 2+ Add polyelectrolyte solution to the complex and stir at room temperature for 1-2 hours to obtain polyelectrolyte complex Eu 3+ ,Tb 3+ ,Zn 2+ Down-conversion luminescent material of the complex;

[0013] The preparation method is a preparation method for NaGdF4:Yb,Er upconversion nanoparticles: GdCl3·6H2O, YbCl3·6H2O and ErCl3·6H2O are mixed with oleic acid and octadecene (ODE) in a container, stirred and heated to form a clear and uniform solution, and cooled; a methanol solution containing NaOH and NH4F is added and stirred; the mixture is slowly heated to 110°C to completely evaporate methanol and water, and degassed at 110°C for 20 minutes; the mixture is heated to 300°C and maintained under nitrogen protection for 1.5 hours; after the reaction is completed, the mixture is cooled to room temperature, washed with ethanol and centrifuged three times to obtain NaGdF4:Yb,Er nanoparticles.

[0014] The preparation method comprises the following steps: after preparing NaGdF4:Yb,Er upconversion nanoparticles, a certain amount of water-soluble polymer is added for modification; the water-soluble polymer is one of polyethylene glycol (PEG), polyvinyl pyrrolidone (PVP), polyvinyl alcohol (PVA), polyacrylamide (PAM), and polyacrylic acid (PAA); the modified NaGdF4:Yb,Er nanoparticles have enhanced hydrophilicity, and can be better dispersed in a solvent when preparing luminescent ink, thereby ensuring the stability and uniformity of the ink.

[0015] The preparation method comprises the following steps: the dispersant is one of sodium metaphosphate (SHMP), sodium dodecylbenzene sulfonate (SDBS), polyvinyl alcohol (PVA) and polyvinyl pyrrolidone (PVP); the thickener is one of gum arabic (GA), gelatin (Gelatin), acrylic resin (AR) and glycerol (GLY); the volume ratio of the dispersant and the thickener to the ethanol solvent is adjusted, and in the ink mixture, the dispersant accounts for 10%-20%, the thickener accounts for 30%-40%, and the mixture is ultrasonically treated for 0.5h-1h to obtain uniform ink.

[0016] (1) Multimodal interactive regulation of luminescence

[0017] The luminescent ink is dual-mode excited by 365nm ultraviolet light and 980nm near-infrared light. Multimodal luminescence interaction is achieved by regulating the wavelength, intensity and sequence of the excitation light. RGB three-color fluorescence is emitted under 365nm ultraviolet light excitation, and green and red light are emitted under 980nm near-infrared light excitation. A variety of different fluorescence coding combinations are achieved to meet the needs of multimodal luminescence interaction for efficient information storage and complex pattern design, and to achieve multi-level encoding and dynamic hiding of information.

[0018] (2) Complex pattern preparation

[0019] Using electrohydrodynamic (EHD) printing technology, the luminescent ink is deposited on the substrate surface to achieve precise pattern printing with a line width of about 20-150μm. During the printing process, the printing parameters are monitored and controlled in real time to ensure the accuracy and stability of the pattern.

[0020] (3) Information storage and sensing function realization

[0021] The prepared complex pattern is invisible under natural light, but displays independent fluorescence signals under UV / NIR dual-mode excitation. It has a sensitive fluorescence quenching response to drugs and most heavy metal ions. The quenching process is reversible after the introduction of EDTA, and at least three cycles of fluorescence recovery and inhibition can be achieved. The selective spraying of heavy metal ion solution and EDTA solution can achieve local fluorescence quenching and recovery, and dynamically control information display and hiding. By monitoring and analyzing the fluorescence signal, the sensing detection of target substances such as heavy metal ions in the environment can be achieved.

[0022] In the process of preparing complex patterns, a variety of printing modes can be used, such as printing, jet printing, vertex spinning, and electrohydrodynamic printing technologies, and the relevant parameters of printing can be adjusted in real time. For example, if electrohydrodynamic printing technology is used, the voltage is 10-30kV, the flow rate is 0.1-1μL / min, and the distance between the nozzle and the substrate is 5-10mm to ensure the stability and consistency of printing. EHD printing can achieve precise pattern printing of dots and lines with a line width and size of 20-150μm. The printed pattern is invisible under natural light, and the encrypted information is read by dual-mode excitation of 250-390nm ultraviolet and 980nm near-infrared light.

[0023] Each luminescent ink was injected into an empty needle of an EHD printer, and a pre-designed pattern was printed onto a substrate via an EHD printer connected to a computer, and photographs of the pattern on the printed paper were taken under a 365nm or 980nm excitation lamp.

[0024] The drugs include fluorouracil (5-FU), methotrexate (MTX), paclitaxel (PTX), vincristine (VCR), gefitinib (Gef), pembrolizumab (Pembro), nivolumab (Nivo), niclosamide (NIC), and temozolomide (TMZ).

[0025] The reversible response is achieved by spraying 1-200 μg / mL Cu 2+ Solution-triggered fluorescence quenching, quenching efficiency and Cu 2+ The fluorescence intensity was linearly related to the concentration; the fluorescence was restored by spraying EDTA solution, and the fluorescence intensity decay rate was ≤15% after being recycled for ≥3 times.

[0026] By adjusting the fluorescence intensity ratio of the down-conversion and up-conversion materials; adjusting the ratio of the four luminescent materials in the pattern distribution: UV light source covers 60-80% of the pattern area, and NIR light source covers the remaining area; changing the excitation order of the excitation light source: UV first then NIR or NIR first then UV or simultaneous excitation of UV and NIR; regulating the intensity of the excitation light; selectively quenching different types of luminescent materials; the luminescent color, intensity, response performance, etc. of the luminescent pattern can be regulated to achieve a variety of different fluorescence coding combinations to meet the needs of multi-level data encoding and dynamic information hiding.

[0027] The up-down conversion multimodal luminescent material prepared according to the preparation method is used in the production of multimodal anti-counterfeiting labels, confidential information storage media, and on-site rapid detection equipment for harmful heavy metal ions and drugs in the environment.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] The unique luminescent ink system constructed by the collaboration of down-conversion complexes and up-conversion nanoparticles can achieve multi-color luminescence output under ultraviolet and near-infrared light excitation, realize dual-mode independent signal reading, and meet the needs of multi-level data encoding and dynamic information hiding. This luminescent ink far exceeds the performance of existing technologies in detection sensitivity, reversibility and anti-interference ability, and can be used more accurately for monitoring harmful heavy metal ions in the environment. After the introduction of EDTA, the quenching is reversible, the recovery rate is ≥90%, it can be cycled multiple times, the fluorescence intensity degradation is small, and it shows high stability and reversibility, ensuring reliability and reusability in practical applications, and supporting dynamic information hiding and rewriting. This luminescent ink is specially formulated for EHD printing technology, which can realize accurate pattern printing with a line width of about 20-50μm. The printed pattern is invisible under natural light, obvious under excitation light, and has good continuous printing stability, which improves the level of printing technology in printing accuracy, pattern concealment and stability, making the present invention more advantageous in making high-security anti-counterfeiting labels, information storage and detection of harmful heavy metal ions in the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 The polyelectrolyte solution HA composite Eu prepared in Example 1 3+ The morphology of the HA-Eu(TTA)3Phen complex;

[0031] Figure 2 The polyelectrolyte solution HA composite Tb prepared in Example 2 3+ The morphology of the complex HA-Tb(AcAc)3Phen complex;

[0032] Figure 3 The polyelectrolyte solution HA composite Zn prepared in Example 3 2+ The morphology of the HA-Zn(BTZ) complex;

[0033] Figure 4 This is a morphology image of PAA-NaGdF4:Yb,Er nanoparticles prepared in Example 4;

[0034] Figure 5 The selectivity of HA-Eu(TTA)3Phen(a), HA-Tb(AcAc)3Phen(b), HA-Zn(BTZ)(c), and PAA-NaGdF4:Yb, Er complex (d) for metal ions in Example 5;

[0035] Figure 6 Detection of different concentrations of Cu in Example 6 2+ Fluorescence intensity change diagram of HA-Eu(TTA)3Phen, HA-Tb(AcAc)3Phen, HA-Zn(BTZ), PAA-NaGdF4:Yb, Er complexes under the condition of 40°C;

[0036] Figure 7 This is a graph showing the change in fluorescence intensity of the HA-Eu(TTA)3Phen complex under different concentrations of niclosamide detected in Example 7;

[0037] Figure 8 This is a graph showing the change in fluorescence intensity of the HA-Tb(AcAc)3Phen complex under different concentrations of temozolomide detected in Example 8;

[0038] Fig. 9 The image of the down-conversion and up-conversion luminescent material ink prepared in Example 9 printed by an EHD printer under 365nm or 980nm excitation light has a line width of 20-50μm.

[0039] Fig.10 The down-conversion luminescent material ink and up-conversion nanoparticle ink prepared in Example 10 were printed by EHD, and the designed fluorescent pattern was revealed under the simultaneous excitation of ultraviolet light and near-infrared light. 2+ After spraying the quencher, the pattern information disappears, and after spraying the EDTA revival agent, the pattern information recovers and appears. This process can be carried out three times in a row.

[0040] Fig.11 The fluorescent pattern after the down-conversion luminescent material ink and the up-conversion nanoparticle ink of Example 11 are printed by EHD is Cu 2+ Fluorescence intensity changes after quenching and EDTA resurrection cycles for 3 times. DETAILED DESCRIPTION

[0041] The present invention is described in detail below in conjunction with specific embodiments.

[0042] Example 1

[0043] EuCl3·6H2O(1.0×10 -3 mol / L), TTA(3.0×10 -1 mol / L) and Phen(1.0×10 -3 mol / L) were dissolved in ethanol respectively, 1mL EuCl3·6H2O and 1mL TTA were mixed, stirred at room temperature for 0.5 hour, diluted ammonia was added to adjust the pH to 7-8, 1mL Phen was added, and the mixture was stirred at room temperature for 2 hours to obtain Eu(TTA)3Phen complex, 1mL polyelectrolyte HA solution was added, and the mixture was stirred at room temperature for 2 hours to obtain HA-Eu(TTA)3Phen complex.

[0044] Figure 1The TEM morphology of the prepared HA-Eu(TTA)3Phen complex shows a spherical nanoparticle structure of uniform size, which has good dispersion stability and is more stably dispersed in the ink solution. It is not prone to problems such as precipitation or agglomeration that clogs the nozzle, which is beneficial to ensure the smoothness of the fluorescent ink during the printing process when preparing the pattern.

[0045] Example 2

[0046] TbCl3·6H2O(1.0×10 -1 mol / L), AcAc(3.0×10 -1 mol / L) and Phen(1.0×10 -3 mol / L) were dissolved in ethanol, 1 mL TbCl3·6H2O and 1 mL AcAc were mixed, stirred at room temperature for 0.5 h, diluted ammonia was added to adjust the pH to 7-8, 1 mL Phen was added, and the mixture was stirred at room temperature for 2 h to obtain Tb(AcAc)3Phen complex, 1 mL polyelectrolyte HA solution was added, and the mixture was stirred at room temperature for 2 h to obtain HA-Tb(AcAc)3Phen complex.

[0047] Figure 2 The morphology of the prepared HA-Tb(AcAc)3Phen composite shows spherical nanoparticles with regular shape and uniform particle size. They can be evenly distributed in the ink and can give full play to the Tb 3+ The fluorescence characteristics of the fluorescent ink are evenly distributed, which improves the display effect of the fluorescent ink.

[0048] Example 3

[0049] ZnCl2(2.0×10 -2 mol / L), BTZ(2.0×10 -2 mol / L) were dissolved in ethanol respectively, 1 mL ZnCl2 and 1 mL BTZ were mixed, and the mixture was stirred at room temperature for 2 hours to obtain the Zn(BTZ) complex, and 1 mL polyelectrolyte HA solution was added, and the mixture was stirred at room temperature for 2 hours to obtain the HA-Zn(BTZ) complex.

[0050] Figure 3 The morphology of the prepared HA-Zn(BTZ) composite shows spherical nanoparticles with regular shapes and uniform particle distribution, indicating that the composite has good dispersibility, making Zn 2+ The complex can exist stably in the ink, ensuring the stability and usability of the fluorescent ink.

[0051] Example 4

[0052] 0.78mmol GdCl3·6H2O, 0.2mmol YbCl3·6H2O and 0.02mmol ErCl3·6H2O were mixed with 8mL oleic acid and 12mL octadecene (ODE) in a flask, stirred and heated to 150℃ to form a clear and uniform solution, and cooled to 50℃; 9mL methanol solution containing 2.5mmol NaOH and 4mmol NH4F was added and stirred for 30 minutes; slowly heated to 110℃ to completely evaporate methanol and water, and degassed at 110℃ for 20 minutes; heated to 300℃ and maintained under nitrogen protection for 1.5 hours; after the reaction, cooled to room temperature, washed with ethanol and centrifuged three times to obtain NaGdF4:Yb,Er nanoparticles. The obtained upconversion nanoparticles were redispersed in 10 mL of cyclohexane, and 10 mL of ethanol solution containing 1.58 g of PAA was added to the flask in sequence and stirred at room temperature for 6 hours. After the reaction, the mixed solution was washed three times with ethanol and deionized water and centrifuged. The product was vacuum dried at 60°C for 10 hours to obtain hydrophilic PAA-NaGdF4:Yb,Er nanoparticles.

[0053] Figure 4 The morphology of the prepared PAA-NaGdF4:Yb,Er nanoparticles shows spherical nanoparticles with regular size and uniform distribution. When preparing luminescent ink, they can be better dispersed in the solvent to ensure the stability and uniformity of the ink.

[0054] Example 5

[0055] The HA-Eu(TTA)3Phen complex prepared in Example 1, the HA-Tb(AcAc)3Phen complex prepared in Example 2, the HA-Zn(BTZ) complex prepared in Example 3, and the PAA-NaGdF4:Yb,Er nanoparticles prepared in Example 4 were subjected to selective detection of metal ions. The metal ion stock solution with a concentration of 1M includes: potassium (K), calcium (Ca), magnesium (Mg), nickel (Ni), iron (Fe), and copper (Cu). 1mL of 1M different drug solutions were added to the solutions prepared in Examples 1, 2, 3, and 4, respectively, and then stirred at 800 rpm for 0.5 hours at room temperature for fluorescence spectrum testing. In all fluorescence spectrum measurements, Eu 3+ The excitation wavelength is 382nm, the emission wavelength is 612nm, the emission slit width is 0.5nm, and Tb 3+ The excitation wavelength is 334nm, the emission wavelength is 546nm, the emission slit width is 0.5nm, and the Zn 2+ The excitation wavelength of PAA-NaGdF4:Yb,Er nanoparticles is 420nm, the emission wavelength is 462nm, and the emission slit width is 1nm. The excitation wavelength of PAA-NaGdF4:Yb,Er nanoparticles is 980nm, the emission wavelength is 544nm, and the emission slit width is 1nm.

[0056] Figure 5 The selectivity of HA-Eu(TTA)3Phen, HA-Tb(AcAc)3Phen, HA-Zn(BTZ), PAA-NaGdF4:Yb, Er complexes for metal ions is shown in Table 1. Compared with other tested metal ions, the luminescent complexes for Cu 2+ The strong fluorescence quenching property indicates that the complex has strong fluorescence quenching property on Cu 2+ special selectivity.

[0057] Example 6

[0058] The HA-Eu(TTA)3Phen complex prepared in Example 1, the HA-Tb(AcAc)3Phen complex prepared in Example 2, the HA-Zn(BTZ) complex prepared in Example 3, and the PAA-NaGdF4:Yb,Er nanoparticles prepared in Example 4 were subjected to Cu 2 + Sensitive detection, preparation of Cu concentrations ranging from 1μg / mL to 200μg / mL 2+ Solution. 1mL of different concentrations of Cu 2+ The solution was added to the solution prepared in Examples 1, 2, 3, and 4 and stirred at room temperature for 0.5 hours. The obtained sample was tested for fluorescence spectrum. 3+ The excitation wavelength is 382nm, the emission wavelength is 612nm, the emission slit width is 0.5nm, and Tb 3+ The excitation wavelength is 334nm, the emission wavelength is 546nm, the emission slit width is 0.5nm, and the Zn 2+ The excitation wavelength of PAA-NaGdF4:Yb,Er nanoparticles is 420nm, the emission wavelength is 462nm, and the emission slit width is 1nm. The excitation wavelength of PAA-NaGdF4:Yb,Er nanoparticles is 980nm, the emission wavelength is 544nm, and the emission slit width is 1nm. Figure 6 It can be seen that at a certain Cu 2+ Concentration range, as Cu 2+ With the increase of concentration, the luminescence intensity of down-conversion and up-conversion luminescence solutions decreased significantly, indicating that Cu 2+ The addition of can effectively quench the fluorescence.

[0059] Figure 6 To detect different concentrations of Cu 2+ The fluorescence intensity change diagram of HA-Eu(TTA)3Phen,HA-Tb(AcAc)3Phen,HA-Zn(BTZ),PAA-NaGdF4:Yb,Er complex is shown below. 2+With the increase of concentration, the fluorescence intensity of the complex decreased greatly, and the fluorescence quenching was obvious, and even completely quenched, indicating that Cu 2+ Its fluorescence can be effectively quenched.

[0060] Example 7

[0061] The HA-Eu(TTA)3Phen complex prepared in Example 1 was subjected to niclosamide sensitivity test, and irinotecan solutions with concentrations ranging from 1ug / mL to 100μg / mL were prepared. 1mL of niclosamide solution of different concentrations was added to the solution prepared in Example 1 and stirred at room temperature for 0.5 hours before fluorescence spectrum test. In all fluorescence spectrum measurements, Eu 3+ The excitation wavelength is 382nm, the emission wavelength is 612nm, and the emission slit width is 0.5nm. Figure 7 It can be seen that within a certain range of niclosamide concentrations, as the concentration of niclosamide increases, the luminescence intensity of the mixed solution decreases significantly, indicating that the addition of niclosamide can effectively quench its fluorescence.

[0062] Figure 7 To detect the change in fluorescence intensity of the HA-Eu(TTA)3Phen complex under different concentrations of niclosamide, within a certain range of niclosamide concentrations, as the concentration of niclosamide increases, the fluorescence intensity of the complex decreases significantly, indicating that niclosamide can effectively quench its fluorescence.

[0063] Example 8

[0064] The HA-Tb(AcAc)3Phen complex prepared in Example 2 was subjected to temozolomide sensitivity detection, and temozolomide solutions with concentrations ranging from 1uM to 200uM were prepared. 1mL of temozolomide solution of different concentrations was added to the solution prepared in Example 2 and stirred at room temperature for 0.5 hours before fluorescence spectrum testing. In all fluorescence spectrum measurements, Tb 3+ The excitation wavelength is 334nm, the emission wavelength is 546nm, and the emission slit width is 0.5nm. Figure 8 It can be seen that within a certain range of temozolomide concentrations, as the temozolomide concentration increases, the luminescence intensity of the mixed solution decreases significantly, indicating that the addition of temozolomide can effectively quench its fluorescence.

[0065] Figure 8 To detect the change in fluorescence intensity of the HA-Tb(AcAc)3Phen complex under different concentrations of temozolomide, within a certain range of temozolomide concentrations, as the concentration of temozolomide increases, the fluorescence intensity of the complex decreases significantly, indicating that temozolomide can effectively quench its fluorescence.

[0066] Example 9

[0067] 5 mL of down-conversion solution and 5 mg of up-conversion nanoparticles were placed in a mixed solvent of ethanol, PVP and glycerol, respectively, with a total volume of 10 mL. In order to obtain inks with optimal viscosity and surface tension, the volume ratio of ethanol, PVP and glycerol was maintained at 5:2:3. After the above down-conversion solution and up-conversion nanoparticle solution were mixed evenly with the mixed solvent, four fluorescent inks were obtained: HA-Eu(TTA)3Phen, HA-Tb(AcAc)3Phen, HA-Zn(BTZ), PAA-NaGdF4:Yb, Er were used as red, green, blue and green inks, respectively. Each solution was directly used as an anti-counterfeiting ink. Each luminescent ink was injected into an empty needle of an EHD printer. The pre-designed pattern was printed on paper using an EHD printer connected to a computer without using a fluorescent agent. With the voltage set to 10-30 kV, the flow rate to 0.1-1 μL / min, and the distance between the nozzle and the substrate to 5-10 mm, precise pattern printing with a line width of 20-50 μm can be achieved using EHD printing, and photographs of patterns on printed paper can be taken under an excitation lamp of 365 nm or 980 nm.

[0068] Fig. 9 The pattern of four straight lines of EHD-printed down-conversion and up-conversion luminescent material inks under 365nm or 980nm excitation light is shown. Figure (a) is made of Eu 3+ The red straight line pattern produced by the complex fluorescent ink, Figure (b) is composed of Tb 3+ The green straight line pattern produced by the complex fluorescent ink, Figure (c) is composed of Zn 2+ The blue straight line pattern produced by the complex fluorescent ink, and the green straight line pattern produced by the PAA-NaGdF4:Yb,Er fluorescent ink in Figure (d) show that the luminescent complex ink emits different colors of fluorescence under UV / NIR excitation light. The printing process is well applicable to this ink, with regular and clear lines, uniform line width and spacing, and a line width of 20-50μm.

[0069] Example 10

[0070] The ink was deposited on the surface of the non-fluorescent paper substrate using EHD printing technology, and the two-dimensional code pattern was printed according to the printing parameters described in Example 9, and the encrypted information was read by dual-mode excitation. 2+ The solution was used to quench the fluorescence and hide the information. The fluorescence information was restored by spraying 0.1M EDTA solution. The operation was repeated 3 times. The prepared pattern was invisible under natural light. Under the excitation of 365nm ultraviolet light and 980nm near-infrared light, Eu 3+ / Tb 3+ / Zn 2+The down-conversion material of the complex and HA and the up-conversion material of NaGdF4:Yb,Er nanoparticles with a core-shell structure and combined with PAA emit fluorescence respectively. By using a light source with corresponding wavelengths for excitation, the red, green, and blue fluorescence from the down-conversion material under ultraviolet excitation, as well as the fluorescence from the up-conversion material under near-infrared excitation can be individually identified and recorded, achieving dual-mode independent signal reading. By adjusting the fluorescence intensity ratio of the down-conversion and up-conversion materials; regulating the intensity of the excitation light; adjusting the proportion of the four luminescent materials in the pattern distribution: UV light source covers 60-80% of the pattern area, and NIR light source covers the remaining area; changing the excitation order of the excitation light source: UV first then NIR or NIR first then UV or simultaneous excitation of UV and NIR; combining with Cu 2+ / The concentration change of the drug quenches different types of luminescent materials, and the introduction of EDTA revives fluorescence. The pattern realizes a variety of different fluorescence coding combinations due to the fluorescence change, and realizes dynamic updating and hiding of information to meet the needs of multi-level data encoding and dynamic information hiding.

[0071] Fig.10 The application of four composites in EHD printing is demonstrated, and the dual-mode optical properties of the printed patterns are characterized. Fig.10 (a) The pattern prepared by EHD is invisible under natural light. Fig.10 In (b), when excited by ultraviolet light, the red, green and blue fluorescence patterns emitted by the three down-conversion materials are clearly visible. Fig.10 (c) Under near-infrared light excitation, upconversion produces a green fluorescence pattern with visible emission, and the pattern information is fully revealed when UV and NIR are excited simultaneously ( Fig.10 (d)). Fig.10 As shown in (e), when Cu 2+ When the solution was sprayed onto the pattern, the pattern showed complete fluorescence quenching. Then, EDTA was sprayed on the quenched area and the fluorescence was restored ( Fig.10 (f)), and then the second Cu spraying can be performed based on the first restored pattern information. 2+ and EDTA solution, the pattern information is also fully revealed ( Fig.10 (g)). This shows the reversible nature of the fluorescence switching, which can be repeated within three cycles.

[0072] Embodiment 11

[0073] The fluorescent pattern printed by EHD in Example 10 is passed through Cu 2+ The samples obtained before and after quenching and EDTA resurrection were tested for fluorescence spectra of HA-Eu(TTA)3Phen, HA-Tb(AcAc)3Phen, HA-Zn(BTZ), PAA-NaGdF4:Yb, Er. The fluorescence intensity decay rate was ≤15% / time.

[0074] Fig.11 The fluorescent pattern after the down-conversion luminescent material ink and up-conversion nanoparticle ink are printed by EHD is Cu 2+ Fluorescence intensity change after quenching and EDTA quenching and resurrection cycles were used three times. Fig.11 (a) is HA-Eu(TTA)3Phen, Fig.11 (b) is HA-Tb(AcAc)3Phen, Fig.11 (c) is HA-Zn(BTZ), Fig.11 (d) is PAA-NaGdF4:Yb,Er. Although a slight decrease in fluorescence intensity was observed during the successive cycles, the integrity of the encoded information was still preserved. This dual-mode excitation mechanism provides a powerful means for multi-layer information encryption and enhanced anti-counterfeiting applications. In addition, the prepared patterns also show the effect of Cu 2+ selective response.

[0075] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all these improvements and changes should fall within the scope of protection of the appended claims of the present invention.

Claims

1. A method for preparing an up-down conversion multimodal luminescent material, characterized in that: The following steps are involved: The down-conversion material and the up-conversion material are dispersed in anhydrous ethanol solvent respectively, and a dispersant and a thickener are added. After uniform dispersion, a uniform and stable luminescent material is obtained; the down-conversion material is: Eu 3+ Complex and / or Tb 3+ Complex and / or Zn 2+ The complex, Eu 3+ , Tb 3+ and Zn 2+ The complex is compounded with a polyelectrolyte solution to form a stable polyelectrolyte-composite down-conversion luminescent material; the up-conversion material is: NaGdF4:Yb, Er nanoparticles, NaGdF4:Yb, Er nanoparticles modified with a water-soluble polymer to form a stable water-soluble NaGdF4:Yb, Er up-conversion material.

2. The method for preparing the up-down conversion multimodal luminescent material according to claim 1, characterized in that: Eu 3+ Complex or Tb 3+ The preparation method of the complex is: Eu 3+ or Tb 3+ :The stoichiometric ratio of the first organic ligand: the second organic ligand ranges from 1:1:1 to 1:3:1; the first organic ligand is one of 4-mercaptobenzoic acid (4-MBA), p-chlorobenzoic acid (4-CBA), iminooxalic acid (IDA), dibenzoylmethane (DBM), 2-thenoyltrifluoroacetone (TTA), acetylacetone (AcAc), and 1,2-diaminocyclohexane-1,2-diacetic acid (DCTA), and the second organic ligand is one of 2,2-bipyridine (bpy), 2,2-bipyridinedicarboxylic acid (DPA), 8-hydroxyquinoline (8-Hyd), and 1,10-o-phenanthroline (Phen).

3. The method for preparing the up-down conversion multimodal luminescent material according to claim 1, characterized in that: Zn 2+ The preparation method of the complex is: Zn 2 : The stoichiometric ratio of the organic ligand ranges from 1:1 to 1:3; the organic ligand is one of ethylenediamine (EN), ethanolamine (MEA), thiourea (TU), and 2-(2-hydroxyphenyl)benzothiazole (BTZ).

4. The method for preparing the up-down conversion multimodal luminescent material according to claim 1, characterized in that: The polyelectrolyte solution is one of sodium alginate (SA), hyaluronic acid (HA), carboxymethyl cellulose (CMC), and pectin (PGA).

5. The method for preparing the up-down conversion multimodal luminescent material according to claim 1, characterized in that: Eu 3+ / Tb 3+ / Zn 2+ The concentration of complex:polyelectrolyte solution ranges from 1:1 to 4:

1.

6. The method for preparing the up-down conversion multimodal luminescent material according to claim 1, characterized in that: The preparation method of NaGdF4:Yb,Er upconversion nanoparticles is as follows: GdCl3·6H2O, YbCl3·6H2O and ErCl3·6H2O are mixed with oleic acid and octadecene (ODE) in a container, stirred and heated to form a clear and uniform solution, and cooled; a methanol solution containing NaOH and NH4F is added and stirred; the mixture is slowly heated to 110°C to completely evaporate methanol and water, and degassed at 110°C for 20 minutes; the mixture is heated to 300°C and maintained under nitrogen protection for 1.5 hours; after the reaction is completed, the mixture is cooled to room temperature, washed with ethanol and centrifuged three times to obtain NaGdF4:Yb,Er nanoparticles.

7. The up-down conversion multimodal luminescent material prepared by the preparation method according to any one of claims 1 to 6, characterized in that: It includes Eu 3+ Complex, Tb 3+ Complex, Zn 2+ One of the three materials or a combination thereof after the complex is compounded with a polyelectrolyte solution; and a water-soluble NaGdF4:Yb,Er upconversion material formed after NaGdF4:Yb,Er nanoparticles are modified with a water-soluble polymer.

8. Application of the up-down conversion multimodal luminescent material according to claim 7 in the production of multimodal anti-counterfeiting labels, confidential information storage media, and rapid on-site detection of harmful heavy metal ions and drugs in the environment.

9. The use according to claim 8, characterized in that: The drugs are fluorouracil (5-FU), methotrexate (MTX), paclitaxel (PTX), vincristine (VCR), gefitinib (Gef), pembrolizumab (Pembro), nivolumab (Nivo), niclosamide (NIC), and temozolomide (TMZ).

10. The use according to claim 8, characterized in that: The harmful heavy metal ions are Cu 2+ .

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