Preparation method of gold nanorods with different length-diameter ratios

Abstract

The invention relates to a preparation method of gold nanorods with different length-diameter ratios. The gold nanorod has the main characteristics of high sensitivity, capability of providing characteristic fingerprint information and the like on a molecular level, and capability of meeting the requirement on sweat monitoring. The preparation method of the gold nanorods comprises the step of preparing the gold nanorods with different length-diameter ratios by adopting a crystal seed growth method. A seed solution is prepared through a reduction reaction of sodium borohydride on chloroauric acid, and the seed solution is added into the growth solution to further obtain the needed gold nanorod structure. The probe can be combined with a flexible substrate, and biomarkers in sweat can be continuously and closely monitored. Therefore, a sweat detection system is further enriched, and important support is provided for finally realizing clinical application of the SERS sweat sensing patch.

Description

Technical Field

[0001] The invention relates to a method for preparing gold nanorods with different aspect ratios. Background Art

[0002] In recent years, fabric sweat sensors have received extensive attention. This is because sweat collection does not require invasion of the human body, and sweat contains a large amount of biological information. However, traditional detection methods have shortcomings such as rough analysis and complicated processes. In order to overcome the shortcomings of traditional detection methods, surface enhanced Raman scattering technology has been introduced into sweat sensor applications. Raman spectra contain fingerprint information on molecules, and surface enhanced Raman scattering (SERS) provides 10 6 ~10 7 times enhancement, which can be applied to chemistry, analytical science and biomedical research. Summary of the invention

[0003] The problem to be solved by the present invention is that in view of the low sensitivity, complex circuit construction and energy supply of the existing colorimetric and electrochemical sweat analysis methods, a method for preparing gold nanorods for optical detection is provided. The main characteristics of gold nanorods are high sensitivity, and they can provide characteristic "fingerprint" information at the molecular level, etc., which can meet the needs of sweat monitoring. The method for preparing gold nanorods in the present invention is: preparing gold nanorods with different aspect ratios by using a crystal seed growth method. The seed solution is prepared by the reduction reaction of chloroauric acid with sodium borohydride, and the seed solution is added to the growth solution to further obtain the desired gold nanorod structure. The present invention can be combined with a flexible substrate to continuously and closely monitor biomarkers in sweat. These will further enrich the sweat detection system and provide important support for the ultimate realization of the clinical application of SERS sweat sensor patches.

[0004] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0005] (1) Preparation of CTAB: Dissolve a certain amount of CTAB (cetyltrimethylammonium bromide) in deionized water and stir in a water bath for a certain period of time to obtain a CTAB solution.

[0006] (2) Preparation of NaBH4: Dissolve NaBH4 in refrigerated water and stir magnetically for a certain period of time to obtain a NaBH4 solution.

[0007] (3) Preparation of seed solution: Add a certain amount of CTAB, HAuCl4·3H2O, NaBH4 and deionized water into a centrifuge tube in sequence and place it away from light for a period of time.

[0008] (4) Preparation of growth solution: Take a certain amount of CTAB solution, add an appropriate amount of HAuCl4·3H2O, then add different volumes of AgNO3, and then add H2SO4 and LAA in sequence. After sealing and leaving for a period of time, add the seed solution prepared above.

[0009] (5) Preparation of gold nanorods: The above solution was placed away from light for a period of time, and then centrifuged and washed with water.

[0010] Preferably, in step (1-3), the concentration of CTAB is 30-180 mM, the concentration of NaBH4 is 5-20 mM, the amount of HAuCl4·3H2O is 10-30 mM, and the storage time away from light is 10-90 min.

[0011] Preferably, in step (4), the concentration of AgNO3 is 1-20 mM, the concentration of H2SO4 is 0.2-1 M, the concentration of L-AA is 0.05-1.8 M, and the volume of the seed solution is 0.1-0.5 ml.

[0012] The above technical solution has the following beneficial effects:

[0013] (1) The present invention prepares gold nanorods with different aspect ratios, which can effectively enhance the signal intensity of glucose in sweat. The material is considered to have great potential and can be widely used in electrochemical sensors, biosensors and other fields;

[0014] (2) The gold nanorods with different aspect ratios prepared in the present invention have excellent properties such as portability, high sensitivity, high precision, rapidity and accuracy when used in sweat sensors, and the preparation method is simple and the cost is low.

[0015] (3) The gold nanorods with different aspect ratios prepared in the present invention can be used in SERS wearable sensing in the fields of real-time human motion monitoring, medical health testing, etc., showing broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The following drawings are only intended to illustrate and explain the present invention, and are not intended to limit the scope of the present invention.

[0017] Figure 1 : It is the result diagram of Example 1 in the present invention.

[0018] Figure 2 : It is the result diagram of Example 2 in the present invention.

[0019] Figure 3 : It is the result diagram of Example 3 in the present invention. DETAILED DESCRIPTION

[0020] The present invention is described below in conjunction with the accompanying drawings and specific embodiments. Unless otherwise specified, the technical means used in the present invention are methods known to those skilled in the art. In addition, the embodiments should be understood as illustrative rather than limiting the scope of the present invention, and the essence and scope of the present invention are limited only by the claims. For those skilled in the art, various changes or modifications to the material composition and dosage in these embodiments, without departing from the essence and scope of the present invention, also belong to the protection scope of the present invention.

[0021] Example 1: TEM image of gold nanorods, calculated, Figure 1 The aspect ratio of the gold nanorods is 3.65

[0022] Example 2: TEM image of gold nanorods, calculated, Figure 2 The aspect ratio of the gold nanorods is 2.53

[0023] Example 3: TEM image of gold nanorods. It is calculated that: Figure 3 The aspect ratio of the gold nanorods is 1.69.

Claims

1. A method for preparing gold nanorods with different aspect ratios, comprising the following steps: (1) Preparation of CTAB: Dissolve a certain amount of CTAB (cetyltrimethylammonium bromide) in deionized water and stir in a water bath for a certain period of time to obtain a CTAB solution. (2) Preparation of NaBH4: Dissolve NaBH4 in refrigerated water and stir magnetically for a certain period of time to obtain a NaBH4 solution. (3) Preparation of seed solution: Add a certain amount of CTAB, HAuCl4·3H2O, NaBH4 and deionized water into a centrifuge tube in sequence and place it away from light for a period of time. (4) Preparation of growth solution: Take a certain amount of CTAB solution, add an appropriate amount of HAuCl4·3H2O, then add different volumes of AgNO3, and then add H2SO4 and LAA in sequence. After sealing and leaving for a period of time, add the seed solution prepared above. (5) Preparation of gold nanorods: The above solution was placed away from light for a period of time and then centrifuged and washed with water.

2. The method for preparing gold nanorods with different aspect ratios according to claim 1, characterized in that: In the above steps (1-3), the concentration of CTAB is 30-180 mM, the concentration of NaBH4 is 5-20 mM, the amount of HAuCl4·3H2O is 10-30 mM, and the storage time away from light is 10-90 min.

3. The method for preparing gold nanorods with different aspect ratios according to claim 1, characterized in that: In the above step (4), the concentration of AgNO3 is 1-20mM, the concentration of H2SO4 is 0.2-1M, the concentration of L-AA is 0.05-1.8M, and the volume of the seed solution is 0.1-0.5ml.

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