阅读说明：本技术 一种多巴胺功能化的金纳米簇的制备方法及其应用 (Preparation method and application of dopamine-functionalized gold nanocluster ) 是由 叶存玲 王远飞 王全坤 王治科 范顺利 于 2019-08-26 设计创作，主要内容包括：本发明公开了一种多巴胺功能化的金纳米簇的制备方法及其应用,属于分析化学技术领域。本发明的技术方案要点为：首先用头孢他啶作为还原剂和保护剂合成了一种新型金纳米簇,并用多巴胺对该金纳米簇进行功能化最终得到多巴胺功能化的金纳米簇,基于该多巴胺功能化的金纳米簇构建的荧光测定体系能够特异性响应对硝基酚和2,4-二硝基酚。本发明所述的多巴胺功能化金纳米簇合成方法简便、反应条件温和且荧光性能优异,基于该多巴胺功能化的金纳米簇构建的荧光测定体系能够特异性响应对硝基酚和2,4-二硝基酚,而且常见酚类对测定几乎没有干扰,在检测对硝基酚和2,4-二硝基酚方面具有实质性的应用前景。(The invention discloses a preparation method and application of a dopamine-functionalized gold nanocluster, and belongs to the technical field of analytical chemistry. The technical scheme provided by the invention has the key points that: firstly, ceftazidime is used as a reducing agent and a protective agent to synthesize a novel gold nano-cluster, dopamine is used for functionalizing the gold nano-cluster to finally obtain the dopamine functionalized gold nano-cluster, and a fluorescence determination system constructed based on the dopamine functionalized gold nano-cluster can specifically respond to p-nitrophenol and 2, 4-dinitrophenol. The dopamine functionalized gold nanocluster is simple and convenient in synthesis method, mild in reaction conditions and excellent in fluorescence performance, a fluorescence determination system constructed on the basis of the dopamine functionalized gold nanocluster can specifically respond to p-nitrophenol and 2, 4-dinitrophenol, common phenols hardly interfere with determination, and the dopamine functionalized gold nanocluster has substantial application prospects in the aspect of detecting p-nitrophenol and 2, 4-dinitrophenol.)

1. A preparation method of a dopamine-functionalized gold nanocluster is characterized by comprising the following specific steps:

Step S1: preparation of AuNCs @ CAZ 0.5mL, 24.28mM HAuCl₄Placing the solution in a 100mL jacketed beaker, adding 6.1mL of 2mM ceftazidime CAZ and 3.4mL of ultrapure water, stirring at 85 ℃ for reaction for 5h, filtering by using a 0.45-micrometer hydrophilic PTFE needle type filter, dialyzing by using a 1kDa dialysis bag, and placing the prepared gold nanoclusters AuNCs @ CAZ in a refrigerator at 4 DEG CStoring in the dark for later use;

Step S2: and (2) preparing AuNCs @ CAZ @ PDA, namely putting 5mL of AuNCs @ CAZ obtained in the step S1 into a 100mL jacketed beaker, adding 5mL of BR buffer solution with the pH =7 and 3mL of absolute ethyl alcohol and 7mL of ultrapure water, reacting at 60 ℃ for 20min, adding 10mg of dopamine DA hydrochloride, stopping the reaction after 5h, centrifuging the solution at 10000rpm for 20min, removing supernatant, re-dispersing the obtained solid AuNCs @ CAZ @ PDA into 20mL of ultrapure water, and placing the solid AuNCs @ CAZ @ PDA in a refrigerator at 4 ℃ in a dark place for later use.

2. The application of the dopamine-functionalized gold nanocluster prepared by the method according to claim 1 in the determination of the concentration of p-nitrophenol is characterized by comprising the following specific steps: taking 2mL of dopamine-functionalized gold nanoclusters AuNCs @ CAZ @ PDA and 0.5mL of PB buffer solution with the pH =9, adding p-nitrophenol to be measured, mixing, fixing the volume to 4.00mL, reacting for 10min at 30 ℃, measuring the fluorescence intensity of a mixed system at an excitation wavelength of 378nm, wherein the linear concentration range of the p-nitrophenol is between 0.75 and 50 mu M, the regression equation is y = -7.8994x +586.68, and the correlation coefficient R is²=0.9913, limit of detection LOD 0.59 μ M, relative standard deviation 1.33% for 11 replicates at 25 μ M added p-nitrophenol concentration.

3. The application of the dopamine-functionalized gold nanocluster prepared by the method according to claim 1 in determination of the concentration of 2, 4-dinitrophenol is characterized by comprising the following specific steps: taking 2mL of dopamine-functionalized gold nanoclusters AuNCs @ CAZ @ PDA and 0.5mL of PB buffer solution with the pH =9, adding 2, 4-dinitrophenol to be detected, mixing, fixing the volume to 4.00mL, reacting for 10min at 30 ℃, determining the fluorescence intensity of a mixed system at an excitation wavelength of 378nm, wherein the linear concentration range of the 2, 4-dinitrophenol is 1-60 mu M, the regression equation is y = -7.3805x +713.46, and the correlation coefficient R is²=0.9921, limit of detection LOD 0.63 μ M, relative standard deviation 2.16% for 11 replicates at 30 μ M concentration of added 2, 4-dinitrophenol.

Technical Field

The invention belongs to the technical field of analytical chemistry, and particularly relates to a preparation method and application of a dopamine-functionalized gold nanocluster.

Background

As a novel fluorescent material, gold nanoclusters are of interest to researchers due to their unique properties. The research and development of novel fluorescent materials mostly focuses on the preparation and application of gold nanoclusters. However, the gold nanoclusters also have the defects of similar emission spectra and single function, and cannot meet higher requirements in the application fields of fluorescence detection and the like.

Disclosure of Invention

The invention solves the technical problem of providing a preparation method of dopamine-functionalized gold nanoclusters, which is simple and convenient in synthesis method, mild in conditions and excellent in fluorescence performance. A fluorescence determination system constructed based on the dopamine-functionalized gold nanocluster can specifically respond to p-nitrophenol and 2, 4-dinitrophenol.

The invention adopts the following technical scheme for solving the technical problems, and the preparation method of the dopamine-functionalized gold nanocluster is characterized by comprising the following specific steps of:

Step S1: preparation of AuNCs @ CAZ 0.5mL, 24.28mM HAuCl₄Placing the solution in a 100mL jacketed beaker, adding 6.1mL of 2mM ceftazidime CAZ and 3.4mL of ultrapure water, stirring and reacting at 85 ℃ for 5h, filtering by using a 0.45-micrometer hydrophilic PTFE needle type filter, dialyzing by using a 1kDa dialysis bag, and placing the prepared gold nanoclusters AuNCs @ CAZ in a refrigerator at 4 ℃ for keeping out of the sun for later use;

Step S2: and (2) preparing AuNCs @ CAZ @ PDA, namely putting 5mL of AuNCs @ CAZ obtained in the step S1 into a 100mL jacketed beaker, adding 5mL of BR buffer solution with the pH =7 and 3mL of absolute ethyl alcohol and 7mL of ultrapure water, reacting at 60 ℃ for 20min, adding 10mg of dopamine DA hydrochloride, stopping the reaction after 5h, centrifuging the solution at 10000rpm for 20min, removing supernatant, re-dispersing the obtained solid AuNCs @ CAZ @ PDA into 20mL of ultrapure water, and placing the solid AuNCs @ CAZ @ PDA in a refrigerator at 4 ℃ in a dark place for later use.

The application of the dopamine functionalized gold nanocluster in the determination of the concentration of p-nitrophenol is characterized by comprising the following specific steps: taking 2mL of dopamine-functionalized gold nanoclusters AuNCs @ CAZ @ PDA and 0.5mL of PB buffer solution with the pH =9, adding p-nitrophenol to be measured, mixing, fixing the volume to 4.00mL, reacting for 10min at 30 ℃, measuring the fluorescence intensity of a mixed system at an excitation wavelength of 378nm, wherein the linear concentration range of the p-nitrophenol is between 0.75 and 50 mu M, the regression equation is y = -7.8994x +586.68, and the correlation coefficient R is²=0.9913, limit of detection LOD 0.59 μ M, relative standard deviation 1.33% for 11 replicates at 25 μ M added p-nitrophenol concentration.

The application of the dopamine functionalized gold nanocluster in determination of the concentration of 2, 4-dinitrophenol is characterized by comprising the following specific steps: taking 2mL of dopamine-functionalized gold nanoclusters AuNCs @ CAZ @ PDA and 0.5mL of PB buffer solution with the pH =9, adding 2, 4-dinitrophenol to be detected, mixing, fixing the volume to 4.00mL, reacting for 10min at 30 ℃, determining the fluorescence intensity of a mixed system at an excitation wavelength of 378nm, wherein the linear concentration range of the 2, 4-dinitrophenol is 1-60 mu M, the regression equation is y = -7.3805x +713.46, and the correlation coefficient R is²=0.9921, limit of detection LOD 0.63. mu.M, relative standard deviation 2.16% for 11 replicates with 30. mu.M added 2, 4-dinitrophenol concentration.

The dopamine functionalized gold nanocluster is simple and convenient in synthesis method, mild in reaction conditions and excellent in fluorescence performance, a fluorescence determination system constructed on the basis of the dopamine functionalized gold nanocluster can specifically respond to p-nitrophenol and 2, 4-dinitrophenol, common phenols hardly interfere with determination, and the dopamine functionalized gold nanocluster has substantial application prospects in the aspect of detecting p-nitrophenol and 2, 4-dinitrophenol.

Drawings

FIG. 1 is a graph showing the effect of pH on the fluorescence properties of AuNCs @ CAZ @ PDA.

FIG. 2 is a graph showing the effect of illumination time on fluorescence performance of AuNCs @ CAZ @ PDA.

FIG. 3 is a graph showing the effect of placement time on the fluorescence properties of AuNCs @ CAZ @ PDA.

FIG. 4 is a graph showing the effect of sodium chloride concentration on the fluorescence properties of AuNCs @ CAZ @ PDA.

FIG. 5 is the excitation and emission spectra of AuNCs @ CAZ @ PDA.

FIG. 6 is an infrared spectrum of AuNCs @ CAZ @ PDA, AuNCs @ CAZ and CAZ.

FIG. 7 is the selectivity of the AuNCs @ CAZ @ PDA assay system.

FIG. 8 is a graph of interference of four common phenolic compounds on the determination of nitrophenol.

FIG. 9 is a graph of the interference of four common phenolic compounds with the determination of 2, 4-dinitrophenol.

Detailed Description

The present invention is described in further detail below with reference to examples, but it should not be construed that the scope of the above subject matter of the present invention is limited to the following examples, and that all the technologies realized based on the above subject matter of the present invention belong to the scope of the present invention.