Near-infrared electrochemiluminescence radiation Zn < 2 + > aggregation-induced double-ligand stable gold nanocluster and preparation method thereof

Abstract

According to the method, chloroauric acid is used as a gold source, zinc acetate is used as a zinc source, 11-mercaptoundecanoic acid and D-penicillamine are used as short-chain / long-chain matched double stabilizers, a borane-tert-butylamine complex is used as a reducing agent, and the near-infrared electrochemiluminescence radiation Zn < 2 + > aggregation-induced double-ligand stable gold nanocluster is prepared. And the water-soluble gold nanocluster is successfully prepared. The required raw materials are easy to obtain and have good water solubility, a synthesis device is simple, conditions are mild, and operation is safe. The obtained gold nanocluster is good in stability, compared with the gold nanocluster without Zn < 2 + >, the electrochemical luminescence intensity of the gold nanocluster is improved by about nine times, and near-infrared electrochemical luminescence with the maximum radiation wavelength larger than 850 nanometers can be generated.

Description

Technical Field

[0001] This invention relates to a near-infrared electrochemiluminescence radiation of Zn 2+ The aggregation-induced dual-ligand stabilized gold nanoclusters and their preparation method belong to the field of quantum dot technology. Background Technology

[0002] Since Bard's group first reported the electrochemiluminescence of Si nanoparticles in 2002 (Science 2002, 296, 1293), a series of advances have been made in the electrochemiluminescence of quantum dot-based nanomaterials, represented by II-VI quantum dots (Chem. Rev. 2014, 114, 11027). II-VI quantum dots often contain toxic elements, posing potential environmental and biological toxicity risks. The electrochemiluminescence of biocompatible metal nanoparticles such as gold, silver, and copper is attracting widespread attention. Gold nanoclusters-based ECL radiation systems, which achieve higher electrochemiluminescence efficiency, have also garnered significant interest. Yang et al. discovered that forming rigid conjugated structures on the surface of metal nanoclusters can significantly enhance the electrochemiluminescence of gold nanoclusters. The electrochemiluminescence of the prepared gold nanoclusters is located in the visible light region, with a maximum radiation wavelength of 532 nm (Angew. Chem. Int. Ed. 2019, 58, 6901).

[0003] Aggregation-induced emission is a photophysical phenomenon that significantly enhances non-luminescent or weakly luminescent materials through aggregation; this effect has also been applied to electrochemiluminescence. Hyeon Taeghwan of Yonsei University in South Korea developed a simple synthetic method to introduce Zn into non-luminescent gold nanoclusters. 2+ A highly fluorescent gold mercaptocarboxylate (MHA, C6) complex assembly was synthesized with a fluorescence quantum yield of up to 90%. Furthermore, the ligand chain length and Zn content were investigated. 2+ The effect of 11-mercaptoundecanoic acid (MUA, C11) on the assembly process of AuNCs was investigated, and it was found that it could not induce assembly in aqueous medium (J. Am. Chem. Soc. 2020, 143(1), 326). Recently, Bai et al. sequentially used Zn... 2+ Ag + and Tb 3+ As a series of cations, and using 3-mercaptopropionic acid (MPA, C3)-protected AuNCs as a model host, a near 100% fluorescence quantum yield of AuNCs was achieved (Nat. Commun. 2025, 16 (1), 587). Other researchers have induced Zn... 2+Aggregates, thereby inducing other short-chain (mercaptosuccinic acid (MSA, C4) or D-penicillamine (DPA, C5)) coated Au or Ag NCs [ACS Appl. Nano Mater. 2022, 5 (5), 7571; ACS Sustain. Chem. Eng. 2022, 10 (38), 12730].

[0004] Currently, the aggregation-inducing strategy for gold nanoclusters coated with long-chain stabilizers remains a significant challenge, potentially enabling near-infrared (NIR) emission and thus benefiting bioimaging and spectral-resolved detection technologies. The development of related methods and technologies is of great academic value for promoting the development of long-wavelength electrochemiluminescence systems and further realizing the spectral modulation of electrochemiluminescence, with broad application prospects. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a near-infrared electrochemiluminescence radiation-emitting Zn 2+ Aggregation-induced dual-ligand stabilized gold nanoclusters and their preparation method.

[0006] This invention successfully prepared water-soluble Zn using chloroauric acid as the gold source, zinc acetate as the zinc source, a borane-tert-butylamine complex as a reducing agent, and a long / short chain dual stabilizer as a stabilizer. 2+ Aggregation-induced dual-ligand-stabilized gold nanoclusters, Zn prepared in this invention 2+ Aggregation-induced dual-ligand stabilized gold nanoclusters can generate near-infrared electrochemiluminescence in the long-wavelength region in aqueous systems, with a maximum emission wavelength exceeding 850 nm.

[0007] This invention is achieved through the following technical solution: A near-infrared electrochemiluminescence radiation of Zn 2+ Aggregation-induced dual-ligand stabilized gold nanoclusters were prepared using chloroauric acid as the gold source, zinc acetate as the zinc source, borane-tert-butylamine complex as the reducing agent, and D-penicillamine and 11-mercaptoundecanoic acid as stabilizers to obtain water-soluble Zn. 2+ Aggregation-induced gold nanoclusters.

[0008] A near-infrared electrochemiluminescence radiation of Zn 2+ The preparation method of aggregation-induced dual-ligand stabilized gold nanoclusters comprises the following steps: (1) Add 11-mercaptoundecanoic acid and D-penicillamine to deionized water, then add H4AuCl4, and mix evenly by ultrasonication to obtain mixture a; (2) Add zinc acetate and borane-tert-butylamine complex to the mixture a in step (1) and mix evenly by ultrasonication to obtain mixture b; (3) Mixture b was stirred at room temperature to react. The resulting solution was purified by centrifugation with isopropanol, and the precipitate was water-soluble Zn. 2+ Aggregation-induced dual-ligand stabilization of gold nanoclusters.

[0009] This invention is based on Zn 2+ Aggregation-induced reduction of Au was achieved through the online reduction of 11-mercaptoundecanoic acid and D-penicillamine, which acted as short / long chain dual stabilizers. + The principle and method were used to successfully prepare Zn 2+ Aggregation-induced dual-ligand stabilization of gold nanoclusters.

[0010] According to the present invention, preferably, in step (1), the molar ratio of H4AuCl4 to 11-mercaptoundecanoic acid is 10000:(1-5), and more preferably, the molar ratio of H4AuCl4 to 11-mercaptoundecanoic acid is 10000:(1-2).

[0011] According to the present invention, preferably, in step (1), the molar ratio of H4AuCl4 to D-penicillamine is 500:(1-5), and more preferably, the molar ratio of H4AuCl4 to D-penicillamine is 500:(1-2).

[0012] According to the present invention, preferably, in step (1), the concentration of H4AuCl4 in mixture a is 80-110 mM, the concentration of 11-mercaptoundecanoic acid is 4-8 μM, and the concentration of D-penicillamine is 1-8 μM.

[0013] Most preferably, in step (1), the concentration of H4AuCl4 in mixture a is 100mM, the concentration of 11-mercaptoundecanoic acid is 5μM, and the concentration of D-penicillamine is 6.25μM.

[0014] According to the present invention, preferably, in step (2), the molar ratio of zinc acetate to H4AuCl4 in step (1) is (1-5):10000, and more preferably, the molar ratio of zinc acetate to H4AuCl4 in step (1) is 1:10000.

[0015] According to the present invention, preferably, in step (2), the molar ratio of the borane-tert-butylamine complex to H4AuCl4 is (1-5):1000, and more preferably, the molar ratio of the borane-tert-butylamine complex to H4AuCl4 is 1:1000.

[0016] According to the present invention, preferably, in step (2), the concentration of zinc acetate in mixture b is 0.1-0.8 μM and the concentration of borane-tert-butylamine complex is 1-10 μM.

[0017] Most preferably, in step (2), the concentration of zinc acetate in mixture b is 0.45 μM and the concentration of the borane-tert-butylamine complex is 4.5 μM.

[0018] According to the present invention, preferably, in step (3), the stirring time is 12-36 hours, and more preferably, the stirring time is 24 hours.

[0019] According to the present invention, in step (3), the mixed solution Au:Zn:11-mercaptoundecanoic acid:D-penicillamine:mbroane-tert-butylamine complex =10000:1:1:20:10, and the stirring time is 24 hours, the wavelength of electrochemiluminescence of the obtained nanoclusters can reach 882nm.

[0020] According to the present invention, preferably, in step (3), isopropanol is used for centrifugation purification at a speed of 13,000 rpm for a purification time of 5 min, and the volume ratio of isopropanol to gold cluster is 1:1.

[0021] A preferred embodiment of the present invention is a near-infrared electrochemiluminescence radiation of Zn 2+ The preparation method of aggregation-induced dual-ligand stabilized gold nanoclusters comprises the following steps: 1) Add the ligand D-penicillamine and 11-mercaptoundecanoic acid to 3.2 mL of deionized water to make the concentration of D-penicillamine 6.25 μM and the concentration of 11-mercaptoundecanoic acid 5 μM. Then, add 100 μL of HAuCl4·H2O to the above solution to make the concentration of HAuCl4·H2O 100 mM. Adjust the pH to 3.0 with stirring to obtain a mixed solution. 2) The borane-tert-butylamine complex and zinc acetate were added dropwise to the mixture from step 1), bringing the concentration of the borane-tert-butylamine complex to 4.5 μM and the concentration of zinc acetate to 0.45 μM. The mixture was stirred for one day at 1500 rpm / min. After adding the reducing agent, the color of the reaction solution changed from colorless to brown; the resulting solution contained Zn 2+ -DPA / MUA@AuNCs were precipitated with isopropanol, and after centrifugation, excess ligands were removed. The solid sample was then dissolved in ultrapure water to obtain a 2 mg / mL gold nanocluster solution for later use.

[0022] Zn prepared by this invention 2+ Solid samples of -DPA / MUA@AuNCs can be safely stored in a refrigerator for more than one month.

[0023] The aqueous solution of the gold nanocluster material prepared by this invention is wine red, and there is an absorption peak (surface plasmon resonance peak) at 560 nm in the ultraviolet-visible spectrum. Under optimal conditions, the maximum fluorescence emission wavelength of the gold nanocluster is 747 and 816 nm in the near-infrared, and the maximum electrochemiluminescence wavelength is 813 and 882 nm in the near-infrared.

[0024] Technical features and advantages of the present invention: 1. This invention obtains Zn in a one-step method. 2+ Aggregation-induced gold nanoclusters stabilized by 11-mercaptoundecanoic acid and D-penicillamine dual ligands have the advantages of being free of toxic elements, having good biocompatibility, and being stable in storage.

[0025] 2. This invention features simple steps, mild conditions, and safe operation. It can generate near-infrared electrochemiluminescence radiation in an aqueous system, relative to Zn. 2+ The unaggregated gold nanoclusters exhibited a 9-fold increase in ECL radiation, with a maximum radiation wavelength greater than 800 nm. Attached Figure Description

[0026] Figure 1 Zn prepared in Example 1 2+ Fluorescence and UV spectra of aggregation-induced dual-ligand stabilized gold nanoclusters.

[0027] Figure 2 No Zn added 2+ Gold nanoclusters (left image) and Zn from Example 1 2+ Scanning electron microscope image of aggregation-induced dual-ligand stabilized gold nanoclusters (right image).

[0028] Figure 3 Zn prepared in Example 1 2+ X-ray photoelectron spectra of aggregation-induced dual-ligand stabilized gold nanoclusters.

[0029] Figure 4 Zn prepared in Example 1 2+ Fluorescence lifetime spectrum of aggregation-induced dual-ligand stabilized gold nanoclusters.

[0030] Figure 5 Zn in Example 1 2+ Aggregation-induced dual-ligand stabilized gold nanoclusters and unadded Zn 2+ Potentiometric luminescence intensity diagram of dual-ligand stabilized gold nanoclusters; Figure 6 Zn in Example 1 2+ Differential pulse voltammetry of aggregation-induced dual-ligand stabilized gold nanoclusters.

[0031] Figure 7Zn in Example 1 2+ Electrochemiluminescence spectrum of aggregation-induced dual-ligand stabilized gold nanoclusters.

[0032] Figure 8 The electrochemiluminescence (ECL) diagrams for comparative examples 1-4 are potential-electrochemiluminescence intensity diagrams of dual-ligand stabilized gold nanoclusters. Detailed Implementation

[0033] The present invention is further illustrated by the following examples, but is not limited thereto.

[0034] The fluorescence spectra of the gold nanoclusters described in the examples were obtained using an F-4700 fluorescence spectrophotometer. The ultraviolet-visible absorption spectra were obtained using an Agilent Cary 60 UV-Vis spectrophotometer. Electrochemiluminescence spectra were acquired using the GCFG-A electrochemiluminescence spectroscopy acquisition system developed by Shandong Guochen Biotechnology Co., Ltd. The potential window used was 0 ~ 1.6 V, and the scan rate was 50 mV / s.

[0035] Electrochemiluminescence assays were performed using a glassy carbon electrode as the working electrode, an Ag / AgCl electrode as the reference electrode, and a Pt wire as the counter electrode. A gold nanocluster-modified electrode was prepared by drop-coating a 10 μL solution of 2 mg / mL gold nanocluster onto the surface of the working electrode and allowing it to dry. The test solution was a 0.1 mol / L phosphate buffer solution (pH 7.4) containing 10 mmol / L triethanolamine. The collected electrochemiluminescence spectra were integrated spectra of all ECL radiations.

[0036] Example 1 Zn near-infrared electrochemiluminescence radiation 2+ Preparation of aggregation-induced biligand-stabilized gold nanoclusters: 1) Add the ligands D-penicillamine (DPA) and 11-mercaptoundecanoic acid (MUA) to 3.2 mL of deionized water to make the concentration of D-penicillamine 6.25 μM and the concentration of 11-mercaptoundecanoic acid 5 μM. Then, add 100 μL of HAuCl4·H2O to the above solution to make the concentration of HAuCl4·H2O 100 mM. Adjust the pH to 3.0 with stirring to obtain a mixed solution. 2) The borane-tert-butylamine complex and zinc acetate were added dropwise to the mixture from step 1), bringing the concentration of the borane-tert-butylamine complex to 4.5 μM and the concentration of zinc acetate to 0.45 μM. The mixture was stirred for one day at 1500 rpm / min. After adding the reducing agent, the color of the reaction solution changed from colorless to brown; the resulting solution contained Zn 2+-DPA / MUA@AuNCs were precipitated with isopropanol, and excess ligands were removed by centrifugation at 13,000 rpm for 5 min. The volume ratio of isopropanol to gold cluster was 1:1.

[0037] No Zn added 2 + Preparation of dual-ligand stabilized gold nanoclusters: The ligands D-penicillamine (DPA) and 11-mercaptoundecanoic acid (MUA) were added to 3.2 mL of deionized water to make the concentration of D-penicillamine 6.25 μM and 11-mercaptoundecanoic acid 5 μM. Then, 100 μL of HAuCl4·H2O was added to the above solution to make the concentration of HAuCl4·H2O 100 mM, and the pH was adjusted to 3.0 with stirring. Next, the borane tert-butylamine complex (4.5 μM) was added dropwise to the reaction mixture, and stirring was continued at 1500 rpm / min for one day. The resulting DPA / MUA@AuNCs were precipitated with isopropanol, and excess ligands were removed by centrifugation.

[0038] Experimental Example 1 1. Zn collected in Example 1 2+ Aggregation-induced dual-ligand stabilized gold nanoclusters were re-dissolved in ultrapure water to prepare 2 mg / mL solutions for characterizing the optical properties of the gold nanoclusters. The UV and fluorescence spectra of the gold nanoclusters are shown below. Figure 1 .from Figure 1 It can be seen from Zn 2+ The fluorescence of aggregation-induced dual-ligand stabilized gold nanoclusters is located in the near-infrared region, at 747 and 816 nm.

[0039] 2. Zn collected in Example 1 2+ Aggregation-induced dual-ligand stabilized gold nanoclusters and unadded Zn 2+ Aggregation-induced dual-ligand stabilized gold nanoclusters were precipitated and dried into powder. A 1 mg / mL solution prepared from the powder was dropped onto a copper grid to characterize the morphology of the gold nanoclusters. Scanning electron microscopy revealed the following results for the gold nanoclusters: Figure 2 .from Figure 2 It can be seen from Zn 2+ Aggregation-induced dual-ligand stabilized gold nanoclusters (right figure) are larger in size and have a spherical morphology compared to the unzinc-added sample.

[0040] 3. Zn collected in Example 1 2+ X-ray photoelectron spectroscopy of aggregation-induced dual-ligand stabilized gold nanoclusters, see [link to X-ray photoelectron spectroscopy]. Figure 3 It can be seen that Zn 2+ The aggregation-induced dual-ligand stabilized gold nanoclusters contain elements such as gold, zinc, and sulfur, proving that Zn 2+ Synthesis of aggregation-induced dual-ligand stabilized gold nanoclusters.

[0041] 4. Zn collected in Example 1 2+ The fluorescence lifetime spectrum of aggregation-induced dual-ligand stabilized gold nanoclusters is shown in [reference needed]. Figure 4 It can be seen that Zn 2+ The fluorescence lifetime of aggregation-induced dual-ligand-stabilized gold nanoclusters exhibits triple-exponential decay, demonstrating that Zn 2+ Aggregation-induced dual-ligand stabilized gold nanoclusters have a large number of defects on their surface.

[0042] 5. Zn collected in Example 1 2+ Aggregation-induced dual-ligand stabilized gold nanoclusters (solid line) and unadded Zn 2+ Potentiometric luminescence intensity plot of dual-ligand stabilized gold nanoclusters (dotted lines), see [image / data]. Figure 5 It can be seen that the Zn in Example 1 2+ The electrochemiluminescence signal of aggregation-induced dual-ligand stabilized gold nanoclusters relative to unadded Zn 2+ The dual-ligand stabilized gold nanoclusters enhanced the signal by approximately nine times.

[0043] 6. Zn collected in Example 1 2+ Differential pulse voltammetry spectra of aggregation-induced dual-ligand stabilized gold nanoclusters, see [reference needed]. Figure 6 It can be seen that Zn 2+ The aggregation-induced dual-ligand-stabilized gold nanoclusters exhibit two hole injection processes, demonstrating that Zn 2+ Aggregation-induced dual-ligand stabilized gold nanoclusters can generate an electrochemiluminescence process.

[0044] 7. Zn collected in Example 1 2+ Electrochemical spectroscopy of aggregation-induced dual-ligand stabilized gold nanoclusters, see [link to image]. Figure 7 It can be seen that Zn 2+ The electrochemical emission spectra of aggregation-induced dual-ligand stabilized gold nanoclusters are located in the near-infrared range at 813 and 882 nm, a redshift of approximately 66 nm relative to their fluorescence wavelength, confirming that Zn 2+ Aggregation-induced dual-ligand stabilized gold nanoclusters have a large number of defects on their surface.

[0045] Comparative Example 1 Zn 2+ Preparation of aggregation-induced single-ligand stabilized gold nanoclusters: 1) Add the ligand 11-mercaptoundecanoic acid (MUA) to 3.2 mL of deionized water to make the concentration of 11-mercaptoundecanoic acid 5 μM. Then, add 100 μL of HAuCl4·H2O to the above solution to make the concentration of HAuCl4·H2O 100 mM. Adjust the pH to 3.0 with stirring to obtain a mixed solution. 2) The borane-tert-butylamine complex and zinc acetate were added dropwise to the mixture from step 1) to achieve a borane-tert-butylamine complex concentration of 4.5 μM and a zinc acetate concentration of 0.45 μM. The mixture was stirred at 1500 rpm / min for one day to obtain the desired Zn. 2+ - MUA@AuNCs were precipitated with isopropanol, and excess ligands were removed by centrifugation. Their potential-electrochemiluminescence intensity plot is shown below. Figure 8 (The line with alternating horizontal lines and dots) shows that the electrochemiluminescence intensity is much lower than that in Example 1.

[0046] Comparative Example 2 Zn 2+ Preparation of aggregation-induced single-ligand stabilized gold nanoclusters: 1) Add the ligand D-penicillamine to 3.2 mL of deionized water to make the concentration of D-penicillamine 6.25 μM. Then, add 100 μL of HAuCl4·H2O to the above solution to make the concentration of HAuCl4·H2O 100 mM. Adjust the pH to 3.0 with stirring to obtain a mixed solution. 2) The borane-tert-butylamine complex and zinc acetate were added dropwise to the mixture from step 1) to achieve a borane-tert-butylamine complex concentration of 4.5 μM and a zinc acetate concentration of 0.45 μM. The mixture was stirred at 1500 rpm / min for one day to obtain the desired Zn. 2+ -DPA@AuNCs were precipitated with isopropanol, and excess ligands were removed by centrifugation. The potential-electrochemiluminescence intensity diagram is shown below. Figure 8 (Short horizontal line) It can be seen that the electrochemiluminescence intensity is much smaller than that of Example 1.

[0047] Comparative Example 3 Zn 2+ Preparation of aggregation-induced single-ligand stabilized gold nanoclusters: 1) Add D-penicillamine (DPA) and 11-mercaptoundecanoic acid (MUA) to 3.2 mL of deionized water to make the concentration of D-penicillamine 6.25 μM and the concentration of 11-mercaptoundecanoic acid 5 μM. Then, add 100 μL of HAuCl4·H2O to the above solution to make the concentration of HAuCl4·H2O 100 mM. Adjust the pH to 3.0 with stirring to obtain a mixed solution. 2) Zinc acetate was added dropwise to the mixture from step 1) to achieve a zinc acetate concentration of 0.45 μM. The mixture was stirred continuously at 1500 rpm / min for one day. After the addition of the reducing agent, the color of the reaction solution changed from colorless to brown. The resulting Zn... 2+ -DPA / MUA@AuNCs were precipitated with isopropanol, and excess ligands were removed by centrifugation. Their potential-electrochemiluminescence intensity diagram is shown below. Figure 8(Dash and dotted line) It can be seen that the electrochemiluminescence intensity is much smaller than that of Example 1.

[0048] Comparative Example 4 Zn 2+ Preparation of other dual-ligand stabilized gold nanoclusters induced by aggregation (Zn 2+ -DPA / GSH@AuNCs): 1) Add the ligands D-penicillamine (DPA) and glutathione (GSH) to 3.2 mL of deionized water to make the concentration of D-penicillamine 6.25 μM and the concentration of glutathione 5 μM. Then, add 100 μL of HAuCl4·H2O to the above solution to make the concentration of HAuCl4·H2O 100 mM. Adjust the pH to 3.0 with stirring to obtain a mixed solution. 2) Add zinc acetate dropwise to the mixture from step 1) to achieve a zinc acetate concentration of 0.45 μM, and continue stirring at 1500 rpm / min for one day. The resulting Zn 2+ -DPA / GSH@AuNCs were precipitated with isopropanol, and excess ligands were removed by centrifugation. The potential-electrochemiluminescence intensity diagram is shown below. Figure 8 (Solid line) It can be seen that the electrochemiluminescence intensity is much smaller than that of Example 1.

[0049] Example 2 Zn near-infrared electrochemiluminescence radiation 2+ Preparation of aggregation-induced biligand-stabilized gold nanoclusters: 1) Add the ligands D-penicillamine (DPA) and 11-mercaptoundecanoic acid (MUA) to 3.2 mL of deionized water to make the concentration of D-penicillamine 6.05 μM and the concentration of 11-mercaptoundecanoic acid 4.5 μM. Then, add 100 μL of HAuCl4·H2O to the above solution to make the concentration of HAuCl4·H2O 95 mM. Adjust the pH to 3.0 with stirring to obtain a mixed solution. 2) The borane-tert-butylamine complex and zinc acetate were added dropwise to the mixture from step 1), making the concentration of the borane-tert-butylamine complex 5.5 μM and the concentration of zinc acetate 0.35 μM. The mixture was stirred for one day at 1500 rpm / min. After adding the reducing agent, the color of the reaction solution changed from colorless to brown; the resulting solution contained Zn 2+ -DPA / MUA@AuNCs were precipitated with isopropanol, and excess ligands were removed by centrifugation at 13,000 rpm for 5 min. The volume ratio of isopropanol to gold cluster was 1:1.

[0050] Example 3 Zn near-infrared electrochemiluminescence radiation 2+Preparation of aggregation-induced biligand-stabilized gold nanoclusters: 1) Add the ligands D-penicillamine (DPA) and 11-mercaptoundecanoic acid (MUA) to 3.2 mL of deionized water to make the concentration of D-penicillamine 7.25 μM and the concentration of 11-mercaptoundecanoic acid 6.25 μM. Then, add 100 μL of HAuCl4·H2O to the above solution to make the concentration of HAuCl4·H2O 105 mM. Adjust the pH to 3.0 with stirring to obtain a mixed solution. 2) The borane-tert-butylamine complex and zinc acetate were added dropwise to the mixture from step 1), making the concentration of the borane-tert-butylamine complex 6.5 μM and the concentration of zinc acetate 0.52 μM. The mixture was stirred for one day at 1500 rpm / min. After adding the reducing agent, the color of the reaction solution changed from colorless to brown; the resulting solution contained Zn 2+ -DPA / MUA@AuNCs were precipitated with isopropanol, and excess ligands were removed by centrifugation at 13,000 rpm for 5 min. The volume ratio of isopropanol to gold cluster was 1:1.

Claims

1. A near-infrared electrochemiluminescence radiation of Zn 2+ Aggregation-induced dual-ligand stabilized gold nanoclusters were prepared using chloroauric acid as the gold source, zinc acetate as the zinc source, borane-tert-butylamine complex as the reducing agent, and D-penicillamine and 11-mercaptoundecanoic acid as stabilizers to obtain water-soluble Zn. 2+ Aggregation-induced gold nanoclusters.

2. The Zn with near-infrared electrochemiluminescence radiation as described in claim 1 2+ The preparation method of aggregation-induced dual-ligand stabilized gold nanoclusters comprises the following steps: (1) Add 11-mercaptoundecanoic acid and D-penicillamine to deionized water, then add H4AuCl4, and mix evenly by ultrasonication to obtain mixture a; (2) Add zinc acetate and borane-tert-butylamine complex to the mixture a in step (1) and mix evenly by ultrasonication to obtain mixture b; (3) Mixture b was stirred at room temperature to react. The resulting solution was purified by centrifugation with isopropanol, and the precipitate was water-soluble Zn. 2+ Aggregation-induced dual-ligand stabilization of gold nanoclusters.

3. The preparation method according to claim 2, characterized in that, In step (1), the molar ratio of H4AuCl4 to 11-mercaptoundecanoic acid is 10000:(1-5).

4. The preparation method according to claim 2, characterized in that, In step (1), the molar ratio of H4AuCl4 to D-penicillamine is 500:(1-5).

5. The preparation method according to claim 2, characterized in that, In step (1), the concentration of H4AuCl4 in mixture a is 80-110 mM, the concentration of 11-mercaptoundecanoic acid is 4-8 μM, and the concentration of D-penicillamine is 1-8 μM.

6. The preparation method according to claim 2, characterized in that, In step (2), the molar ratio of zinc acetate to H4AuCl4 in step (1) is (1-5):10000.

7. The preparation method according to claim 2, characterized in that, In step (2), the molar ratio of the borane-tert-butylamine complex to H4AuCl4 is (1-5):1000.

8. The preparation method according to claim 2, characterized in that, In step (2), the concentration of zinc acetate in mixture b is 0.1-0.8 μM, and the concentration of the borane-tert-butylamine complex is 1-10 μM.

9. The preparation method according to claim 2, characterized in that, In step (3), the stirring time is 12-36 hours.

10. The preparation method according to claim 2, characterized in that, In step (3), isopropanol is used for centrifugation purification at a speed of 13,000 rpm for 5 min. The volume ratio of isopropanol to gold cluster is 1:1.

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