Polypeptide-modified gold nanocluster and preparation method thereof

Abstract

The invention belongs to the technical field of functional biological nanometer materials, and concretely relates to a polypeptide-modified gold nanocluster and a preparation method thereof. Two polypeptides KRKC and GSH are employed ad stabilizing agents for modification during hydrothermal preparation, a red fluorogold nanocluster with targeting marking effect on cell nucleolus by designing polypeptide sequence for guaranteeing stability of metal clusters, and has the particle size within the scope of 1.5-2.8 nm and the average particle size of 1.9 nm, the gold nanocluster has an obvious absorption peak near 400 nm, when a laser of 400 nm is used to irradiate the gold nanocluster, relatively strong fluorescence emission is generated at the region of 500-750 nm, the emission peak is near 586 nm, and the fluorescent quantum yield of the gold nanocluster is 7%. The method is simple, strong in operability and low in cost, the material is stabilized by the polypeptides, has good biocompatibility, and is low in toxicity, good in stability, long in emission wavelength and beneficial for obtaining relatively good nucleolus imaging effect by employing the polypeptides as the stabilizing agents.

Description

Technical field:

[0001] The invention belongs to the technical field of functional biological nanomaterials, and specifically relates to a polypeptide-modified gold nanocluster and a preparation method thereof. Two polypeptides, KRKC and GSH, are used as stabilizers for modification, and the polypeptide sequence is designed to ensure the stability of the metal cluster. Red fluorescent gold nanoclusters with targeted labeling for cellular nucleoli. Background technique:

[0002] The nucleolus is an important subnuclear structure in the nucleus, which plays an important role in the growth and proliferation of cells. In addition, the nucleolus is also the site of rRNA transcription, translation and ribosome assembly in the nucleus, so it is also called the "ribosome factory". It has even been reported in the literature that the nucleolus is also the target attack site of some viruses. The nucleolus does not exist all the time. It is formed during the interphase of cell divisio...

Examples

Embodiment 1

[0022] The preparation method of the polypeptide-modified gold nanocluster involved in this embodiment, the specific process steps are as follows:

[0023] (1) Prepare 20mmol / L HAuCl with ultrapure water 4 , 20mmol / L of KRKC and 20mmol / L of GSH solution, soak the glass bottle with aqua regia, clean it and dry it for later use;

[0024] (2) Add 450 μL of KRKC solution and 150 μL of GSH solution to the treated glass bottle and mix well, then add HAuCl 4 Solution 300μL, it can be observed that the color of the reaction system changes from colorless to light yellow, and finally add ultrapure water to the glass bottle to make the Au in the solution + The final concentration is 2mmol / L;

[0025] (3) Place the glass bottle with the reactants in a constant temperature water bath, and react at a constant temperature of 70°C-80°C for 12 hours;

[0026] (4) After the reaction, transfer the sample to a centrifuge tube and centrifuge to remove macromolecular particles, and filter the ce...

Embodiment 2

[0034] The preparation method of the polypeptide-modified gold nanocluster involved in this embodiment, the specific process steps are as follows:

[0035] (1) Prepare 20mmol / L HAuCl with ultrapure water 4 , 20mmol / L of KRKC and 20mmol / L of GSH solution, soak the glass bottle with aqua regia, clean it and dry it for later use;

[0036] (2) Add 450 μL of KRKC solution and 150 μL of GSH solution to the treated glass bottle and mix well, then add HAuCl 4 Solution 300μL, it can be observed that the color of the reaction system changes from colorless to light yellow, and finally add ultrapure water to the glass bottle to make the Au in the solution + The final concentration is 2mmol / L;

[0037] (3) Place the glass bottle with the reactants in a constant temperature water bath, and react at a constant temperature of 80°C for 12 hours;

[0038] (4) After the reaction is over, transfer the sample to a centrifuge tube and centrifuge to remove macromolecular particles, and add any on...

Technical field:

[0001] The invention belongs to the technical field of functional biological nanomaterials, and specifically relates to a polypeptide-modified gold nanocluster and a preparation method thereof. Two polypeptides, KRKC and GSH, are used as stabilizers for modification, and the polypeptide sequence is designed to ensure the stability of the metal cluster. Red fluorescent gold nanoclusters with targeted labeling for cellular nucleoli. Background technique:

[0002] The nucleolus is an important subnuclear structure in the nucleus, which plays an important role in the growth and proliferation of cells. In addition, the nucleolus is also the site of rRNA transcription, translation and ribosome assembly in the nucleus, so it is also called the "ribosome factory". It has even been reported in the literature that the nucleolus is also the target attack site of some viruses. The nucleolus does not exist all the time. It is formed during the interphase of cell divisio...

Examples

Embodiment 1

[0022] The preparation method of the polypeptide-modified gold nanocluster involved in this embodiment, the specific process steps are as follows:

[0023] (1) Prepare 20mmol / L HAuCl with ultrapure water 4 , 20mmol / L of KRKC and 20mmol / L of GSH solution, soak the glass bottle with aqua regia, clean it and dry it for later use;

[0024] (2) Add 450 μL of KRKC solution and 150 μL of GSH solution to the treated glass bottle and mix well, then add HAuCl 4 Solution 300μL, it can be observed that the color of the reaction system changes from colorless to light yellow, and finally add ultrapure water to the glass bottle to make the Au in the solution + The final concentration is 2mmol / L;

[0025] (3) Place the glass bottle with the reactants in a constant temperature water bath, and react at a constant temperature of 70°C-80°C for 12 hours;

[0026] (4) After the reaction, transfer the sample to a centrifuge tube and centrifuge to remove macromolecular particles, and filter the ce...

Embodiment 2

[0034] The preparation method of the polypeptide-modified gold nanocluster involved in this embodiment, the specific process steps are as follows:

[0035] (1) Prepare 20mmol / L HAuCl with ultrapure water 4 , 20mmol / L of KRKC and 20mmol / L of GSH solution, soak the glass bottle with aqua regia, clean it and dry it for later use;

[0036] (2) Add 450 μL of KRKC solution and 150 μL of GSH solution to the treated glass bottle and mix well, then add HAuCl 4 Solution 300μL, it can be observed that the color of the reaction system changes from colorless to light yellow, and finally add ultrapure water to the glass bottle to make the Au in the solution + The final concentration is 2mmol / L;

[0037] (3) Place the glass bottle with the reactants in a constant temperature water bath, and react at a constant temperature of 80°C for 12 hours;

[0038] (4) After the reaction is over, transfer the sample to a centrifuge tube and centrifuge to remove macromolecular particles, and add any on...

Images