Marquise

Uses of gold

Gold, when used as a coloring agent in cranberry glass, produces a deep, intense red color.

In photography, gold toners are used to change the color of black and white silver bromide prints to brown or blue colors or to increase their stability. Gold toners used in brown prints produce red colors. Kodak published formulas for several types of gold toner that use gold as chloride.

Gold is a good reflector of electromagnetic radiation such as infrared and visible light as well as radio waves. It is used for protective coatings on many artificial satellites, in infrared shielding plates in astronaut thermal suits and helmets, and in electronic warfare aircraft such as the EA-6B Prowler.  Gold. is used as a reflective layer in some high-end CDs.

Cars may use gold for heat protection. McLaren uses gold leaf in the engine compartment of its F1 model.

Gold can be made so thin that it appears translucent. In some airplane cabin windows, it is used for defrosting or anti-icing by passing electricity through it. The heat from the gold resistance is enough to prevent ice from forming.

The gold is attacked and dissolved in alkaline solutions of potassium or sodium cyanide to form salt gold cyanide – a technique used in the extraction of metallic gold from ore in the cyanide process. Gold cyanide is the electrolyte used in commercial gold plating on base metals and electroforming.

Gold chloride (chloroauric acid) solutions are used to make colloidal gold by reduction with citrate or ascorbate ions. Gold chloride and gold oxide are used to make cranberry or red glasses, which, like colloidal gold suspensions, contain spherical gold nanoparticles of uniform size.

When gold is dispersed in nanoparticles, it can act as a heterogeneous catalyst for chemical reactions.

Other uses of gold include:

• Using gold toners in photo printing to change black and white to brown or blue colors
• Making a Gold Compact Disc
• Heterogeneous Gold Catalysis in the form of nanoparticles

From the applications of gold in medicine Apart from medical uses such as making medicines and such, we can mention the making of surgical instruments, use in some artificial parts of the body, the making of some laboratory equipment such as accurate thermometers, etc. 

Gene therapy with gold element

Gold nanoparticles are used in gene therapy, which is a method of treating disease through the repair of defective genes.

Photothermal therapy

Gold nanorods have been used as photothermal agents in photothermal therapy (PTT) research. In this treatment method, electromagnetic radiation, which is usually in infrared wavelengths, is used to treat various diseases, including cancer.

Biosensor

The use of gold nanoparticles in biosensors increases their stability, sensitivity and selectivity. These types of sensors are divided into two main groups: optical and electrochemical biosensors. In electrochemical sensors, biological data is converted into electrical signals.

Gold in dentistry

The relatively good malleability of gold alloys and the ineffectiveness of this element have led to its use in dentistry. The gold element is used in dentistry to restore and cover teeth.

The medicinal use of gold in the form of metal has been popular since ancient times. In the 19th century, this metal was used to treat anxiety, nervous disorders, depression, epilepsy, migraine, amenorrhea, impotence and alcoholism.

In fact, the gold element does not react with any of the chemicals in the body and is ineffective against them, and only its salts and isotopes have medicinal value. For example, stomach acid has no effect on gold.

Medical Imaging

Thin gold coatings are used to observe biological or biological samples and other non-conductive materials such as plastic and glass in the Scanning Electron Microscope (SEM). When gold is irradiated, it produces a lot of secondary electrons. Secondary electrons that have low energy are one of the signal sources of scanning electron microscope. The emission of these electrons is the result of charged particles such as electrons or ions hitting the metal surface in a vacuum tube.

Quick Diagnosis

Colloidal gold is used in the immunogold labeling or staining method (Immunogold labeling | IGS) in the electron microscope for rapid detection or immunoassay. By using this method, colloidal gold particles coated with special antibodies with the characteristic of surface absorption of protein molecules can explore the presence and position of antigens or antigens on the surfaces of cells. These particles can be seen with an electron microscope in highly sensitive findings in the form of dense dots where antigens are present.

In nuclear medicine of 198 Au isotope  whose half-life is only 2.7 days for the treatment of some cancers use. Colloidal nanoparticles are used in cancer research to detect tumors using Surface-enhanced Raman Spectroscopy (SERS).

Drug Delivery

Gold nanoparticles are used in drug delivery to optimize and improve the targeted biodistribution of drugs in organs, tissues or cells. Drug delivery includes unstable drug targets such as proteins, tumors, intracellular organelles, hard-to-reach locations such as the brain, retina, and drugs with serious side effects such as anticancer drugs.