Gold Nanoparticles: Way More Than Elegance And Upvaluation

Today, even technology has been highly developed, most of the gold is still used to process jewelry or as currency. Although only about 10% of gold is used in other technical fields, the impact it brings to our daily lives is still huge. Moreover, gold also plays a greater role in a form that many people may not be familiar with—gold nanoparticles (AuNPs). This article will introduce in detail several applications of gold nanoparticles in social life.

• AuNPs are used as catalysts

Corrosion will not appear when exposing a gold bar to the air or immersing it in water for a long time, because the chemical properties of gold are very stable. However, when its size is reduced to tens or even under ten nanometers, these gold nanoparticles can become very active.

For example, the gold nanoparticle catalyst can efficiently convert carbon monoxide into carbon dioxide. This catalyst has been installed on some racing cars to prevent the driver from being poisoned by carbon monoxide.

• Application of AuNPs in LCD

Behind the Liquid Crystal Display (LCD) screen, a transparent, conductive film is plated to serve as electrodes. When a weak current flows through the electrodes, the color of the liquid crystal there changes, thereby displaying text or pictures. This is why the LCD screen does not require a bulky picture tube.

Traditionally, to manufacture such a film, it is necessary to sputter transparent conductive indium tin oxide onto the liquid crystal panel in a high vacuum environment. This process is complicated in technology and expensive in materials. Recently, scientists in Singapore have found a better way to replace expensive indium tin oxide with gold and reduce the process requirements.

They experimented with a suspension of AuNPs. The size of these gold particles is about 20 nm, while the size of gold atoms is 0.2 nm. In this way, an AuNP contains almost one million gold atoms. They first poured the suspension on a glass plate and let it evaporate. In the process of slow evaporation, these AuNPs gradually move to the bottom of the latex microspheres and settle there to form a honeycomb grid connected by rings.

After the water in the suspension evaporates, they then heat the glass plate to let the latex coated on the surface evaporate, so a very thin, transparent microcircuit made of AuNPs is made. If this kind of method can be used to make microcircuit on the liquid crystal panel, the relatively cheap AuNPs can replace the currently widely used indium tin oxide material.

• Application of AuNPs in drug development

Many diseases, including the threatening AIDS, are caused by the expression of some foreign genes in our cells (such as genes embedded by viruses) as our own genes. But scientists encounter obstacles in the development of specific RNA drugs—these micro RNAs (miRNAs) are broken down before they can take effect after entering cells.

However, recently, scientists have discovered that if AuNPs are used as carriers for miRNA, their survival rate can be greatly improved.

In the experiment, the scientists first bundled miRNAs on AuNPs which are about 13 nanometers in diameter. Each particle was bound with 30 miRNAs and then was placed in the cell culture medium. It was found that within 6 hours, 99% of the short RNA and AuNPs were absorbed into the body by the cells.

In the past, miRNA was broken down within a few minutes after it entered the cell. Now, these miRNAs conjugated to AuNPs can survive for hours or even days, which allows them to have enough time to work.

There are many more applications of gold nanoparticles, and more research is under study. Creative Diagnostics, an experienced expert in nanoparticles, provides various kinds of spherical gold nanoparticles for a wide of applications, hoping to move forward related research.

Thomas Schmitt: Working at a biotechnology company for over 10 years and writing to share the latest technology for over 5 years.