Preparation method of platinum-doped hollow gold nanorod with high photothermal stability

Abstract

The application relates to a preparation method of platinum-doped hollow gold nanorods with high photothermal stability, and belongs to the technical field of nanometer material preparation. A tellurium precursor and a selenium precursor are added into a solution containing hydrazine hydrate and continuously stirred by a magnetic force, and after the reaction is completed, the tellurium selenium nanorods are prepared by dilution with an aqueous solution of sodium dodecyl sulfate; the prepared tellurium selenium nanorods are dispersed in pure water, gold precursors, platinum precursors and modifiers are added at the same time, and then the platinum-doped hollow gold nanorods are prepared by centrifugal separation. The application effectively improves the thermal stability of the hollow gold nanorods by platinum doping, and when the proportion of the platinum doping is 10% and above, the improvement of the photothermal stability of the hollow gold nanorods is very obvious; and the application has a positive significance for fully exerting the effect of the hollow gold nanorods in photothermal treatment and related combined treatment applications.

Description

TECHNICAL FIELD

[0001] The application relates to a preparation method of a platinum-doped hollow gold nanorod with high photothermal stability, and belongs to the technical field of nanometer material preparation. BACKGROUND

[0002] The ripening of gold nanomaterials in solution will change their morphology, and the higher the temperature, the faster the ripening. The optical properties of gold nanomaterials are closely related to their morphology, size and structure. For example, the plasmonic absorption peak of gold nanorods will be obviously red-shifted with the increase of the length-diameter ratio, and when the length-diameter ratio reaches about 6, the absorption peak can be adjusted to the near-infrared second window (1000 nm), and if the gold nanorod is hollow, when the length-diameter ratio reaches about 3, the absorption peak can be adjusted to the near-infrared second window (ACS Appl. Mater. Interfaces, 2018, 10, 36703). The near-infrared second window is more suitable for biomedical applications than the traditional near-infrared first window, because the near-infrared second light source has stronger penetration ability of biological tissues, and the maximum allowable radiation of the near-infrared second light source in the biological body is higher, so the depth of the biological tissue treated by the near-infrared second light source is larger. However, in the process of photothermal application, the heat generated by the hollow gold nanorod will cause the temperature of itself and the surrounding environment to rise, accelerate the ripening of the hollow gold nanorod, and thus cause the morphology to be destroyed and the photothermal conversion property to be reduced, which is very unfavorable for the application based on the photothermal conversion property of the hollow gold nanorod.

[0003] In addition, the hollow gold nanorod is also an effective combination therapy nanocarrier. Studies have shown that combination therapy is a method of combining two or more of chemotherapy, photothermal therapy, photodynamic therapy or immunotherapy, and they are more effective than single treatment method for tumor treatment. Compared with solid nanorods, the hollow structure of hollow gold nanorods has a certain loading capacity, and the uneven structure of the surface increases the specific surface area, which is very favorable for the modification or loading of chemotherapeutic or photodynamic therapeutic drugs. Therefore, as a comprehensive diagnosis and treatment nanoplatform, the hollow gold nanorod has greater potential than the solid gold nanorod in combination therapy. Hollow gold nanorod is one of the few gold nanomaterials that can adjust the plasmonic absorption peak to the near-infrared second window, and in order to fully exert the effect of hollow gold nanorod in photothermal therapy and related combination therapy applications, it is necessary to improve the photothermal stability of hollow gold nanorod. SUMMARY

[0004] The purpose of the present application is to provide a preparation method of a platinum-doped hollow gold nanorod with high photothermal stability in view of the above-mentioned shortcomings or deficiencies of the prior art.

[0005] The technical scheme of the present application is:

[0006] A preparation method of a platinum-doped hollow gold nanorod with high photothermal stability, characterized in that it comprises the following steps:

[0007] (a) adding tellurium precursor and selenium precursor into a solution containing hydrazine hydrate and continuously stirring under magnetic force, the tellurium precursor being tellurium dioxide or tellurous acid, the selenium precursor being selenious acid, the molar ratio being 40:1-100:1; after reacting at a temperature of 30-40 DEG C for 20 min, diluting with an aqueous solution of sodium dodecyl sulfate, and then performing solid-liquid separation to obtain a precipitate, a tellurium-selenium nanorod is obtained;

[0008] (b) dispersing the tellurium-selenium nanorod prepared in step (a) in a 1.0-3.0 μmol / L aqueous solution of cysteine, and then simultaneously adding a gold precursor and a platinum precursor into the solution, the gold precursor being chloroauric acid, and the platinum precursor being chloroplatinic acid or chloroplatinic acid salt; after magnetic stirring for a preset time, centrifugal separation is performed to obtain a platinum-doped hollow gold nanorod.

[0009] In step (b), the platinum precursor accounts for 10%-20% of the molar ratio of the gold and platinum noble metals; and the reaction temperature of the noble metal precursor in the aqueous solution of cysteine is 10-30 DEG C.

[0010] The platinum-doped hollow gold nanorod in step (b) comprises a shell and a hollow region formed by the shell.

[0011] The present application has the following beneficial effects compared with the prior art:

[0012] The present application effectively improves the thermal stability of the hollow gold nanorod by platinum doping, and when the doping ratio of platinum is 10% or more, the improvement of the photothermal stability of the hollow gold nanorod is very obvious; and this has a positive significance for fully exerting the effect of the hollow gold nanorod in photothermal therapy and related combined therapy applications. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 is an absorption spectrum diagram of a hollow gold nanorod without doping platinum after irradiation with a laser of different power;

[0014] Figure 2 is a TEM diagram of a hollow gold nanorod without doping platinum;

[0015] Figure 3 is a change in the ratio of the absorbance of a hollow gold nanorod of the present application with different platinum doping contents after irradiation with a laser of different power to the absorbance before irradiation;

[0016] Figure 4 is a TEM diagram of a hollow gold nanorod doped with 20% platinum of the present application;

[0017] Figure 5The process flow chart of the present application. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application is further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and do not limit the present application. In addition, the technical features involved in each embodiment of the present application described below can be combined with each other as long as they do not conflict with each other.

[0019] The preparation method of the platinum-doped hollow gold nanorod with high photothermal stability is as follows:

[0020] (a) The tellurium precursor and the selenium precursor are added to the hydrazine hydrate solution and continuously stirred by magnetic force, the tellurium precursor is tellurium dioxide or tellurous acid, the selenium precursor is selenious acid, and the molar ratio is 40:1-100:1; after reacting at a temperature of 30-40℃ for 20 min, the reaction solution is diluted with an aqueous solution of sodium dodecyl sulfate, and then solid-liquid separation is performed to obtain a precipitate, thereby obtaining tellurium selenium nanorods;

[0021] (b) The tellurium selenium nanorods prepared in step (a) are dispersed in 1.0-3.0 μmol / L of cysteine, and then gold precursor and platinum precursor are simultaneously added to the solution, the gold precursor is chloroauric acid, and the platinum precursor is chloroplatinic acid or chloroplatinic acid salt; the reaction is stirred by magnetic force for a preset time, and centrifugal separation is performed to obtain platinum-doped hollow gold nanorods.

[0022] In step (b), the molar ratio of the platinum precursor to the gold and platinum noble metals is 10%-20%; the reaction temperature of the platinum precursor and the gold precursor in the cysteine solution is 10-30℃.

[0023] In step (b), the platinum-doped hollow gold nanorod includes a shell and a hollow region formed by the shell.

[0024] The present application is further described below according to specific examples. Example 1

[0025] (a) According to a molar ratio of 100:1, tellurium dioxide and selenious acid are added to a hydrazine hydrate solution, and the reaction is fully stirred at a temperature of 40℃; after 20 min, the reaction solution is transferred into a solution containing sodium dodecyl sulfate, and after fully stirring for 10 min, centrifugal separation is performed to obtain a precipitate, thereby obtaining tellurium selenium nanorods;

[0026] (b) The tellurium-selenium nanorods prepared in step (a) were dispersed in 3.0 μmol / L aqueous solution of cysteine, and then stirred magnetically at a temperature of 30 °C. Gold chloride and platinum chloride solutions were added, with a molar ratio of gold chloride to platinum chloride of 9:1. The mixture was stirred for 10 min, and then centrifuged to obtain platinum-doped hollow gold nanorods. Example 2

[0027] (a) Tellurous acid and selenious acid were added to a hydrazine hydrate solution, and stirred at a temperature of 35 °C, with a molar ratio of tellurous acid to selenious acid of 40:1. After 20 min, the reaction solution was transferred into a solution containing sodium dodecyl sulfate, and stirred for 10 min. The precipitate was obtained by centrifugation to obtain tellurium-selenium nanorods;

[0028] (b) The tellurium-selenium nanorods prepared in step (a) were dispersed in 1.0 μmol / L aqueous solution of cysteine, and then stirred magnetically at a temperature of 20 °C. Gold chloride and platinum chloride solutions were added, with a molar ratio of gold chloride to platinum chloride of 4:1. The mixture was stirred for 15 min, and then centrifuged to obtain platinum-doped hollow gold nanorods. Example 3

[0029] (a) Tellurium dioxide and selenious acid were added to a hydrazine hydrate solution, with a molar ratio of 100:1, and stirred at a temperature of 40 °C. After 20 min, the reaction solution was transferred into a solution containing sodium dodecyl sulfate, and stirred for 10 min. The precipitate was obtained by centrifugation to obtain tellurium-selenium nanorods;

[0030] (b) The tellurium-selenium nanorods prepared in step (a) were dispersed in 2.0 μmol / L aqueous solution of cysteine, and then stirred magnetically at a temperature of 25 °C. Gold chloride and platinum chloride solutions were added, with a molar ratio of gold chloride to platinum chloride of 19:1. The mixture was stirred for 10 min, and then centrifuged to obtain platinum-doped hollow gold nanorods. Example 4

[0031] (a) Tellurium dioxide and selenious acid were added to a hydrazine hydrate solution, with a molar ratio of 100:1, and stirred at a temperature of 40 °C. After 20 min, the reaction solution was transferred into a solution containing sodium dodecyl sulfate, and stirred for 10 min. The precipitate was obtained by centrifugation to obtain tellurium-selenium nanorods;

[0032] (b), the tellurium selenium nanorods prepared in step (a) are dispersed in a 2.0 μmol / L aqueous solution of cysteine, magnetic stirring is carried out at a temperature of 20 ℃, then a chloroauric acid and chloroplatinic acid solution is added, the molar ratio of the chloroauric acid and chloroplatinic acid being 17:3, stirring is carried out for 10 min, centrifugal separation is carried out, and platinum-doped hollow gold nanorods are obtained.

[0033] Example 5 (comparative example)

[0034] (a), tellurous acid and selenious acid are added to a hydrazine hydrate solution, stirring is carried out at a temperature of 35 ℃, the molar ratio of the tellurous acid and selenious acid being 80:1, after the reaction is carried out for 20 min, the reaction solution is transferred into a solution containing sodium dodecyl sulfate, stirring is carried out for 10 min, and then centrifugal separation is carried out to obtain a precipitate, and tellurium selenium nanorods are prepared;

[0035] (b), the tellurium selenium nanorods prepared in step (a) are dispersed in a 2.0 μmol / L aqueous solution of cysteine, magnetic stirring is carried out at a temperature of 25 ℃, then a chloroauric acid solution is added, stirring is carried out for 10 min, centrifugal separation is carried out, and hollow gold nanorods without platinum doping are obtained.

[0036] In order to verify the thermal stability of the platinum-doped hollow gold nanorods prepared in the application, the inventors used a 1064 nm laser which is commonly used in the second near-infrared region as a test condition, and tested the spectrum of the hollow gold nanorods without doping after irradiation with different power lasers (see Figure 1 ), Figure 2 is a TEM image of the hollow gold nanorods. From Figure 1 it can be seen that as the laser power increases, the hollow gold nanorods have a greater wavelength difference in the blue shift of the position of the plasmonic absorption peak, and the absorbance at 1064 nm decreases more greatly. After irradiation with a 2.48 W laser, the absorbance at 1064 nm decreased by nearly 50% compared with before irradiation. In order to make a better comparison, the inventors prepared hollow gold nanorods doped with platinum precursors in conditions in which the molar ratio of platinum precursors to gold and platinum noble metals was 5%, 10%, 15% and 20% respectively, and then tested the photothermal properties of the hollow gold nanorods prepared under the four different platinum doping conditions, and then calculated the ratio of the absorbance after irradiation with different power lasers to the absorbance before irradiation, and compared this with the hollow gold nanorods without doping (see Figure 3 ). The results show that the absorbance of the hollow gold nanorods doped with 5% platinum decreased more obviously, the decrease was more than 10% after irradiation with a 1.82 W laser, and the decrease was more than 20% after irradiation with a 2.48 W laser, while the decrease of the other three hollow gold nanorods was less than 10%. The smaller the decrease, the higher the thermal stability of the material. The highest was the hollow gold nanorods doped with 20% platinum precursors,Figure 4 TEM images of platinum-doped hollow gold nanorods. Although the absorbance of 5% platinum-doped hollow gold nanorods decreased more obviously, the decrease in their absorbance was more than halved compared to the decrease in the absorbance of non-doped hollow gold nanorods. In summary, the method of improving the stability of hollow gold nanorods by platinum doping is effective and feasible.

Claims

1. A method for preparing platinum-doped hollow gold nanorods with high photothermal stability, characterized in that, It includes the following steps: (a) The tellurium precursor and the selenium precursor are added to a solution containing hydrazine hydrate and continuously stirred magnetically. The tellurium precursor is tellurium dioxide or tellurite, and the selenium precursor is selenite. The molar ratio is 40:1 to 100:

1. After reacting for 20 min at a temperature of 30 to 40 °C, the mixture is diluted with an aqueous solution of sodium dodecyl sulfate and then subjected to solid-liquid separation to obtain a precipitate, thus obtaining tellurium selenide nanorods. (b) Disperse the tellurium selenide nanorods obtained in step (a) in 1.0~3.0 μmol / L cysteine, and then add gold precursor and platinum precursor to the solution at the same time. The gold precursor is chloroauric acid, and the platinum precursor is chloroplatinic acid or chloroplatinate. Stir the reaction magnetically for 10 or 15 min, and centrifuge to obtain platinum-doped hollow gold nanorods. In step (b), the platinum precursor material accounts for 10% to 20% of the molar ratio of gold and platinum; the reaction temperature of the platinum precursor material and the gold precursor material in the cysteine ​​solution is 10 to 30 °C. The platinum-doped hollow gold nanorod in step (b) includes a shell and a hollow region formed by the shell.

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