Michael Faraday and the Birth of Colloidal Gold
Long before the words nanoparticles, nanotechnology or nanomedicine existed, Michael Faraday created one of the most important gold based materials in scientific history: ruby red colloidal
In 1857, Michael Faraday investigated what he called “divided gold”, tiny particles of gold suspended in liquid. Today, these are recognised as early gold nanoparticles and some of the first metallic gold colloids ever scientifically documented.
The Royal Institution notes that Faraday’s gold colloids were made in the basement laboratory at the Ri and are among the first examples of metallic gold colloids, produced over 150 years ago. Some of these samples remain optically active today, meaning they still interact with light in a way that reveals suspended particles inside the liquid.
Faraday noticed a ruby coloured fluid during experiments with very thin gold films. When light was shone through the liquid, suspended particles scattered the beam, creating what became known as the Faraday Tyndall effect.
Who Was Michael Faraday?
Michael Faraday was one of the most influential scientists of the nineteenth century. His work helped shape modern electricity, electromagnetism, electrochemistry and experimental physics.
Faraday is often remembered for electromagnetic induction, motors and generators. Yet his work with gold colloids is equally fascinating because it places him at the very beginning of nanoscience.
At the time, Faraday could not see nanoparticles directly. Electron microscopes did not exist. But through observation, light experiments and careful reasoning, he realised that the ruby liquid contained particles of gold too small for the scientific apparatus of the period to resolve.
What Is Colloidal Gold?
Colloidal gold is a suspension of tiny particles of elemental gold dispersed throughout a liquid, usually purified water. Unlike dissolved gold salts, true colloidal gold contains actual gold particles.
When gold particles are reduced to the nanoscale, they behave differently from bulk metallic gold. A gold bar appears yellow because it reflects light from a large metallic surface. Gold nanoparticles, however, interact with light through their surface electrons, creating colours ranging from ruby red to purple depending on particle size, shape and
How Gold Becomes Colloidal Gold
Modern colloidal gold production is far more controlled than nineteenth century chemistry, but the principle remains beautifully simple: pure gold is transformed into microscopic particles and suspended throughout purified
1. Pure Gold Source
A 24K gold source provides the elemental gold material used to create nanoscale particles.
2. Controlled Energy
Electrical or chemical processes separate tiny particles from the gold source under controlled conditions.
3. Nanoparticles Form
Gold particles form at the nanoscale, often within a range where optical properties become highly distinctive.
4. Ruby Red Suspension
When light interacts with the particles, the liquid can display the famous ruby red appearance.
Why Is Colloidal Gold Ruby Red?
The ruby red colour of colloidal gold is not a dye, flavouring or pigment. It is caused by physics at the nanoscale.
When light hits gold nanoparticles, electrons on the particle surface begin to oscillate together. This collective movement of electrons is known as surface plasmon resonance. The nanoparticles absorb and scatter selected wavelengths of light, leaving the liquid with its characteristic red
Surface plasmon resonance is one of the reasons gold nanoparticles are used in modern biosensors, optical research, diagnostics and nanomedicine. Their colour and light response can change depending on particle size, shape, surrounding molecules and aggregation state.
Why Particle Size Changes Everything
At the nanoscale, materials can display properties that do not appear in larger forms of the same substance. This is one reason gold nanoparticles became so important in modern science.
A particle between 5 and 100 nanometres wide is incredibly small. For comparison, a human hair is roughly 80,000 nanometres wide, while a red blood cell is around 7,000 nanometres
As particle size decreases, surface area increases dramatically. This gives nanoparticles more active surface relative to their mass, which can influence optical behaviour, electrical properties and interactions with surrounding molecules.
The same metal can behave differently depending on scale. Bulk gold appears yellow and metallic. Nanoscale gold can appear ruby red because the surface electrons interact with light differently.
Faraday, Light and the Faraday Tyndall Effect
Faraday did not have modern imaging technology, but he did have extraordinary experimental skill. When he shone light through his gold colloids, he observed a visible cone of light inside the liquid.
The Royal Institution describes Faraday’s notebook observation that “the cone was well defined in the fluid by the illuminated particles”. This is the Faraday Tyndall effect: light scattering from particles suspended in a liquid.
This observation helped Faraday understand that the ruby fluid contained tiny suspended particles, even though those particles were too small to see directly.
How Gold Nanoparticles Interact with Biological Systems
Gold nanoparticles are now widely studied in modern biomedical research because their size, surface chemistry and optical properties can be precisely engineered. This does not mean every wellness claim about colloidal gold is proven, but it does explain why gold nanoparticles attract serious scientific
In nanomedicine research, gold nanoparticles are explored for imaging, biosensing, delivery systems, photothermal applications and cellular interaction studies. Their behaviour depends heavily on size, surface charge, coating, particle shape and the biological environment.
Cellular Interaction
Nanoparticles may interact with cell membranes, proteins and signalling systems depending on their surface chemistry.
Surface Reactivity
The particle surface can bind or interact with molecules, which is why gold nanoparticles are useful in biosensor design.
Optical Response
Gold nanoparticles strongly interact with visible light, making them valuable in optical detection research.
Research Caution
Scientific interest does not equal proven health outcomes. Human effects depend on formulation, exposure route and study design.
Gold and the Brain: A Modern Research Frontier
Gold nanoparticles are also being explored within neuroscience and brain related nanomedicine research. This includes experimental work on imaging, blood brain barrier delivery systems, neuroinflammation models and neural
The blood brain barrier is highly selective. Some research investigates whether specifically engineered nanoparticles can cross or interact with this barrier under controlled experimental conditions. This is very different from claiming that any commercial colloidal gold product automatically crosses the blood brain barrier.
Gold nanoparticles are studied in neuroscience, but this does not mean colloidal gold is a treatment for neurological conditions. The responsible position is that gold nanoparticle research is promising, highly technical and still developing.
Scientifically Studied Benefits of Gold Nanoparticles
Many studies investigate gold nanoparticles for their potential roles in oxidative stress modulation, inflammatory signalling, immune interactions, biosensing, imaging and cellular energy
The most responsible way to discuss this science is to separate laboratory research from consumer wellness claims. Gold nanoparticles may show interesting effects in experimental models, but clinical relevance depends on dose, particle size, coating, route of exposure and safety data.
The Journey From Faraday to Nanomedicine
Faraday’s accidental ruby red liquid became a scientific bridge between Victorian chemistry and twenty first century
His work showed that gold could be reduced into tiny suspended particles with optical properties unlike bulk metal. Today, that same principle sits behind research in plasmonics, nanomedicine, biosensors, imaging and advanced materials.
Why Faraday’s Original Gold Colloids Still Matter
One of the most remarkable details from the Royal Institution collection is that Faraday’s original colloids remain optically active after more than 150 years. Most colloids last months or perhaps a year, making the survival of Faraday’s samples scientifically unusual.
For Gold Healing, this history matters because it reminds us that colloidal gold is not just a modern wellness trend. It is rooted in one of the earliest chapters of nanoscience.
Explore 24K Colloidal Gold
Gold Healing 24K Colloidal Gold is inspired by the remarkable history of gold nanoparticles, from Faraday’s ruby red colloids to modern interest in nanoscale gold.
Frequently Asked Questions
Did Michael Faraday invent colloidal gold?
Faraday did not invent gold nanoparticles in the modern manufacturing sense, but he was one of the first scientists to document and study metallic gold colloids in detail.
Why is colloidal gold red?
Colloidal gold appears ruby red because gold nanoparticles interact with light through surface plasmon resonance.
What are gold nanoparticles?
Gold nanoparticles are tiny particles of elemental gold measured in nanometres, which are billionths of a metre.
Are gold nanoparticles used in science today?
Yes. Gold nanoparticles are studied in nanomedicine, biosensors, imaging, diagnostics, plasmonics and advanced materials science.
Is ruby red colloidal gold natural?
The ruby red colour can naturally occur when gold nanoparticles are correctly formed and dispersed. The colour comes from light interacting with the nanoscale particles.
Can colloidal gold support brain health?
Gold nanoparticles are studied in neuroscience research, but this does not prove that colloidal gold treats or prevents brain conditions. Current evidence should be discussed cautiously.
References and Scientific Context
- Royal Institution. “Michael Faraday’s gold colloids.” The Ri collection notes that these liquids are among the first examples of metallic gold colloids and describes Faraday’s ruby fluid, light scattering observations and the long term optical activity of the samples. View source
- Faraday, M. “The Bakerian Lecture: Experimental Relations of Gold and Other Metals to Light.” Philosophical Transactions of the Royal Society, 1857.
- Research literature on localized surface plasmon resonance explains how conduction electrons on gold nanoparticle surfaces oscillate with incident light, producing distinctive optical colours.
- Modern nanomedicine literature continues to explore gold nanoparticles for biosensing, imaging, drug delivery systems, photothermal research and cellular interaction studies.
