纳米金粒子技术手册（一）
基于应用的黄金纳米粒子产品选择
| Application | Gold Nanoparticle Size Range |
Surface Chemistry | Benefits | Related Documents |
| Protein Conjugation | 5nm-100nm | standard (citrate) | Quick | Classic Passive Adsorption of Proteins to Gold Nanoparticles |
| NHS | Covalent conjugation to primary amines, increased stability, less non-specific protein binding. | Conjugation of proteins to NHS-activated gold nanoparticles | ||
| Maleimide | Covalent conjugation to thiol groups, increased stability, less non-specific protein binding. | - | ||
| Carboxyl | Covalent conjugation, increased stability, less non-specific protein binding. | Covalent conjugation of proteins to carboxyl gold nanoparticles | ||
| Amine | Conjugation of carboxylated ligands | - | ||
| Streptavidin | Can be used with any biotinylated ligand, ideal for high-throughput screenings. | - | ||
| Modification with thiolated ligands (PEG-SH etc.) |
5nm-100nm | standard (citrate) | Classic starting material, no additional stabilizers added | - |
| stabilized (surfactant) | Increased stability during functionalization but reduced kinetics | - | ||
| Oligonucleotide Conjugation | 5nm-15nm | standard (citrate) | Ideal for conjugation of thiolated oligonucleotides to small particle sizes. | - |
| 5nm-100nm | OligoREADY™ | Ideal for conjugation of thiol modified oligos to particles between 5nm-100nm in diameter. | - | |
| 5nm-100nm | Maleimide | Ideal for covalent conjugation of thiol modified oligos to particles between 5nm-100nm in diameter. | - | |
| 5nm-100nm | NHS | For covalent conjugation of amine functionalized oligonucleotides. Ideal when a linker is required between the gold surface and conjugated oligonucleotide. |
- | |
| Immuno-dot blot/Western blot | 5nm-20nm | Protein conjugated gold nanoparticles (antibodies, streptavidin etc) | Colorimetric straightforward detection (no equipment required) Generates a permanent label |
Immunoblotting protocol for gold conjugates |
| Immunohistochemistry (TEM) | 5nm-40nm | Protein conjugated gold nanoparticles (antibodies, streptavidin etc) | High contrast label | - |
| Flow Cytometry | 50nm-400nm | Gold Size Standards | Ideal for standardization of results between runs and experiments when analyzing particles in the 50nm-400nm range. | - |
| Cellular Uptake | 30nm-60nm | Transferrin gold conjugate | Active uptake through endocytosis | - |
| Standard (citrate) | Non-specific cellular uptake | - | ||
| Cationic gold (available upon request) | High efficiency non-specific cellular uptake | - | ||
| Darkfield Microscopy | 50nm-100nm | Gold conjugates | - | - |
| Lateral Flow/Dip-Stick Assays | 30nm-80nm | Standard (citrate) | Allows for development of rapid testing kit, point of care assays | Lateral flow immunoassays |
| NHS | ||||
| Carboxyl | ||||
| Amine | ||||
| Streptavidin | ||||
| Protein A | ||||
| Protein G | ||||
| Tumor Targeting | 30nm-80nm | methoxy-PEG | Allows for passive targeting of certain tumors in vivo Inert material with low non-specific protein binding in serum |
- |
| Light Microscopy | 5nm-10nm | Gold secondary antibody conjugates | Ability to label tissue sections for both light and electron microscopy. Alternative to peroxidase and PAP based stains. Sensitivity can be enhanced with silver enhancement techniques |
- |
| ELISA | 5nm-30nm | Gold antibody conjugates | Straightforward colorimetric detection |
我怎么洗我的金纳米粒子吗?
对于大多数应用程序可以使用我们的金纳米粒子没有任何额外的清洗步骤。 如果你有一个敏感的应用程序,需要额外的清洗的最佳方式是通过离心或过滤。 推荐的离心速度和时间请参考
When stored for a long period of time the gold nanoparticles might sediment at the bottom of the flask, which is especially true for larger particle sizes. Prior to use, re-suspend the sedimented particles by swirling until a homogenous solution is obtained.
To maintain optimal performance, and stability of the colloidal gold, care should be taken to use clean storage containers if using other than supplied with the product.
Characterization of Gold Nanoparticles
Please read our "Introduction to Gold Nanoparticle Characterization" tech note for information on how to analyze gold nanoparticles and their properties.
Washing of Gold Nanoparticles
Although it is not always necessary to wash the gold nanoparticles prior to use, some applications might require additional washing procedures. The easiest way to remove possible contaminants in the nanoparticles solution is by centrifugation. Centrifugation force is dependant on size of the gold nanoparticles and should be adjusted according to table I for optimal performance.
Note:
Since non-functionalized gold nanoparticles are sensitive to salt containing buffers, re-suspension should always be performed in ultra-pure water to prevent irreversible aggregation. Irreversible aggregation is characterized by a clear to bluish solution upon the addition of salt.
Procedure
- Place aliquot of colloidal gold in appropriate centrifuge tube.*
- Centrifuge the gold nanoparticles for 30 minutes using the appropriate G force depending on size of the gold nanoparticles, see Table I.
- Remove supernatant and re-suspend in appropriate volume of ultra-pure water.
- Vortex to re-disperse particles.
*Note: Addition of Tween 20 to a final concentration of 0.025% (w/v) at this step improves performance during centrifugation and can prevent the formation of aggregates. However, Tween 20 binds to the gold surface and can slightly affect the adsorption of other molecules to the gold surface.
Table I. Appropriate G forces for centrifugation of gold nanoparticles. Note that recommended conditions are for a volume of 1ml and centrifugation using a microcentrifuge, except for 5nm gold nanoparticles that requires an ultracentrifuge.
| Size (nm) | Speed (g) | Time (min) |
|---|---|---|
| 5 | 100,000 | 30 |
| 10 | 17,000 | 60 (~50% recovery) |
| 15 | 17,000 | 30 |
| 20 | 6,500 | 30 |
| 30 | 4,500 | 30 |
| 40 | 2,500 | 30 |
| 50 | 2,000 | 30 |
| 60 | 1,125 | 30 |
| 80 | 600 | 30 |
| 100 | 400 | 30 |
| 150 | 180 | 30 |
| 200 | 100 | 30 |
处理
当存储在很长一段时间 金纳米粒子 可能在烧瓶底部的沉积物,特别是较大的粒子大小。 使用之前,re-suspend沉淀粒子的旋转,直到齐次解。
保持最佳性能,稳定的胶体金,应该小心使用干净的存储容器如果使用除了提供产品。
金纳米粒子的表征
请阅读我们的“ 介绍金纳米粒子特性 “信息技术注意如何分析金纳米粒子及其属性。
洗的金纳米粒子
尽管它并不总是必要洗金纳米粒子使用之前,一些应用程序可能需要额外的清洗程序。 可能最简单的方法去除污染物在纳米粒子溶液离心分离。 离心力依赖于金纳米粒子的大小,应根据表调整为最佳性能。
注意:
自non-functionalized金纳米粒子对盐敏感包含缓冲区,re-suspension总是应该在超纯水,防止不可逆聚合。 添加盐是一个不可逆聚合。
过程
- 地方整除的 胶体金 在合适的离心管。*
- 离心机30分钟的金纳米粒子使用适当的G力根据金纳米粒子的大小不同,见下表。
- 去除上层清液和re-suspend适当体积的超纯水。
- 涡re-disperse粒子。
*注意:添加渐变20的终浓度0.025%(w / v)在离心这一步提高了性能,可以防止骨料的形成。 然而,渐变20金表面结合,可以稍微影响其他分子的吸附金的表面。
表我。 适当的G力离心金纳米粒子。 注意,推荐条件1毫升的体积和使用微型离心机离心,除了5纳米金纳米粒子,需要一个超离心机。
| 大小(nm) | 速度( g ) | 时间(分钟) |
|---|---|---|
| 5 | 100000年 | 30 |
| 10 | 17000年 | 60(~ 50%恢复) |
| 15 | 17000年 | 30 |
| 20 | 6500年 | 30 |
| 30 | 4500年 | 30 |
| 40 | 2500年 | 30 |
| 50 | 2000年 | 30 |
| 60 | 1125年 | 30 |
| 80年 | 600年 | 30 |
| 100年 | 400年 | 30 |
| 150年 | 180年 | 30 |
| 200年 | 100年 | 30 |
我该什么黄金纳米颗粒大小选择对于我的应用程序?
金纳米颗粒的大小和表面化学是非常依赖于应用程序使用。 请参阅我们的 黄金纳米粒子产品选择指南 找到最优的产品为您的特定应用程序。
我的金纳米粒子在存储的解决方案。 这是正常的吗?
的金纳米粒子沉降存储瓶的底部是完全正常的,常用于大尺寸的颗粒,以更大的速度解决。 沉淀不影响粒子的性能。 使用之前,只是漩涡解决适当分散你的金纳米粒子和生成一个同质的解决方案。
金纳米粒子的保质期是什么?
我们的标准金纳米粒子稳定至少1年如果存储未开封和指定的在4摄氏度。 不存储non-functionalized标准金纳米粒子在冰箱里因为这导致不可逆转的聚合,看到我们吗 金纳米粒子处理和存储 技术报告。
金纳米粒子溶液变成紫色当我添加包含缓冲盐。 这是为什么呢?
由于排斥力的金纳米粒子的表面电荷,单个粒子的能量势垒必须克服互动。 当没有(或小)大量的电解质,如氯化钠存在,这种能量势垒过于强烈的粒子之间的相互作用发生。 然而,在添加氯化钠这能量势垒降低使金纳米粒子相互作用和聚合。 这聚合会导致一个现象称为表面等离子体耦合,改变光到一个更高的吸附最大波长从而产生的颜色变化的解决方案。
如果我不小心冻结non-functionalized金纳米粒子吗?
冻结我们的non-functionalized金纳米粒子引起不可逆转的聚合,可以观察到明显的颜色变化的解决方案,见我们 金纳米粒子处理和存储 技术的更多信息和示例,请注意。
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