CN-121975514-A - Method for regulating and controlling luminescence of Au nanoclusters by solvent-induced ligand isomerization

Abstract

The invention is suitable for the technical field of chemical materials, and provides a method for regulating and controlling luminescence of Au nanoclusters by solvent-induced ligand isomerization, which comprises the steps of firstly synthesizing the Au nanoclusters with different surface isomer ratios by regulating the pH value of a reaction system; and then introducing the fluorescent dye into a system containing a specific organic solvent, and inducing reversible conversion between Au (I) -thione and Au (I) -mercaptan isomer by utilizing the interaction of solvent molecules and a cluster surface ligand structure and synergistically regulating proton coupling electron transfer kinetics, so that the accurate regulation of the luminescence performance of the nano cluster is realized. The invention can realize broadband, continuous and reversible adjustment of the luminescence wavelength within the range of 495 nm-800 nm under mild conditions, remarkably improves the luminescence quantum yield, has the advantages of simple operation, clear mechanism and green universality, and has application prospects in the fields of biological imaging, optical sensing, luminescent devices and the like.

Inventors

• BAI XUE
• WANG XUE
• LU MIN
• WU ZHENNAN
• ZHANG YU
• ZHANG FUJUN

Assignees

• 吉林大学

Dates

Publication Date

20260505

Application Date

20260128

Claims (6)

1. 1. The method for regulating and controlling the luminescence of the Au nanoclusters by using the solvent-induced ligand isomerization is characterized by comprising the following steps of: Step 1, synthesizing aqueous gold nanoclusters; 6-MPR is used as a ligand, reacts with HAuCl 4 in a water phase, and synthesizes gold nanoclusters with different surface ligand isomer ratios by regulating and controlling the pH value of a reaction system; Step 2, solvation regulation; introducing the gold nanoclusters obtained in the step 1 into a system containing an organic solvent, inducing ligand isomerization conversion by utilizing the interaction of the organic solvent and a ligand structure on the surface of the nanoclusters, and regulating proton coupling electron transfer kinetics of the nanoclusters so as to regulate and control the luminescence property of the nanoclusters.
2. 2. The method of claim 1, wherein in step 1, the pH of the reaction system is 6.5, 7, 9, 11, 13 or 13.5.
3. 3. The method of claim 1, wherein in step 1, the molar mass ratio of 6-MPR to HAuCl 4 is 2:1.
4. 4. The method of claim 1, wherein in step 2, the organic solvent is selected from a strongly coordinating aprotic solvent and/or a high viscosity protic solvent.
5. 5. The method of claim 4, wherein the strongly coordinating aprotic solvent is selected from at least one of DMSO, DMAc, and DMF, and the high viscosity protic solvent is selected from at least one of GL, PG, and EG.
6. 6. The method of claim 1, wherein in step 2, the gold nanoclusters are introduced as an aqueous solution, and the volume ratio of the aqueous solution of gold nanoclusters to the organic solvent is 1.5:1, 2:1, 2.5:1, 3.5:1, 5:1, 10:1.

Description

Method for regulating and controlling luminescence of Au nanoclusters by solvent-induced ligand isomerization Technical Field The invention belongs to the technical field of chemical materials, and particularly relates to a method for regulating and controlling luminescence of Au nanoclusters by solvent-induced ligand isomerization. Background Metal Nanoclusters (NCs) are aggregates composed of several to hundreds of metal atoms and protected by a monolayer of organic ligands, with dimensions between a single atom and plasmonic nanoparticles. The material has definite molecular structure, unique electronic energy level and obvious optical property (such as photoluminescence), and has wide application prospect in the fields of sensing, biological imaging, photoelectronic devices, catalysis and the like. Among them, gold nanoclusters are a research hotspot due to good biocompatibility, stable chemical properties and abundant excited state processes of gold elements. The performance of nanomaterials is closely related to the microenvironment in which they are located, while solvents, as the most common medium, play a decisive role in determining the colloidal stability, geometry, surface state and finally the optoelectronic properties of nanoclusters. Solvation can influence nucleation and growth kinetics of the nano material, participate in surface coordination and charge transfer processes, and regulate and control supermolecule assembly behaviors of the nano material. Therefore, the solvent effect is deeply understood and utilized, and is one of key ways for realizing the precise regulation and control of the performance of the nano material. Although solvation has a general impact on the fundamental properties of nanomaterials, there is currently a lack of systematic, clear understanding as to how solvent molecules precisely regulate the intrinsic mechanisms of metal nanoclusters, particularly their excited state electron kinetics and photoluminescence properties. Most of the current research focuses on the effect of solvents on cluster synthesis, crystal structure or static spectra. The key scientific problem of how to influence the conformation of the ligand on the surface of the cluster, change the electronic structure of the ligand and further regulate the luminous color and efficiency of the ligand through dynamic interaction is not fully elucidated and effectively utilized. This results in the current majority of metal nanoclusters emitting a relatively single color of light and being difficult to achieve continuous, reversible tuning over a wide spectral range. In addition, blurring of the luminescence mechanism also limits the ability to rationally design materials based on target properties (e.g., specific emission wavelength, high quantum yield). Therefore, developing a new method with strong universality, clear mechanism and capability of realizing wide-range and fine regulation of the luminous performance of the metal nanoclusters is a technical problem to be solved in the field. Disclosure of Invention The embodiment of the invention aims to provide a method for regulating and controlling luminescence of Au nanoclusters by solvent-induced ligand isomerization, which aims to solve the problems in the background art. The embodiment of the invention is realized in such a way that the solvent-induced ligand isomerization regulates and controls the luminescence of the Au nanoclusters, and the method comprises the following steps: Step 1, synthesizing aqueous gold nanoclusters; 6-mercaptopurine-9-beta-D-ribofuranoside (6-MPR) is taken as a ligand, reacts with chloroauric acid (HAuCl 4) in a water phase, and synthesizes gold nanoclusters with different surface ligand isomer ratios by regulating and controlling the pH value of a reaction system; Step 2, solvation regulation; introducing the gold nanoclusters obtained in the step 1 into a system containing an organic solvent, inducing ligand isomerization conversion by utilizing the interaction of the organic solvent and a ligand structure on the surface of the nanoclusters, and regulating proton coupling electron transfer kinetics of the nanoclusters so as to regulate and control the luminescence property of the nanoclusters. According to a further technical scheme, in the step 1, the pH value of the reaction system is 6.5, 7, 9, 11, 13 or 13.5. According to a further technical scheme, in the step 1, the molar mass ratio of 6-MPR to HAuCl 4 is 2:1. Further technical scheme, in the step 2, the organic solvent is selected from a strong coordination aprotic solvent and/or a high viscosity protic solvent. According to a further technical scheme, the strong coordination aprotic solvent is selected from at least one of dimethyl sulfoxide (DMSO), N-dimethylacetamide (DMAc) and N, N-Dimethylformamide (DMF), and the high-viscosity protic solvent is selected from at least one of Glycerol (GL), 1, 2-Propylene Glycol (PG) and Ethylene Glycol (EG). According to a