Gold nanoparticles

Gold nanoparticles (GNPs) are a promising technology with applications in a wide range of fields including catalysis, electronics, materials science, and healthcare. They are of great interest to researchers because of their unusual optical, electronic, and chemical properties.

They can also be easily synthesized in a variety of shapes, including spheres, rods, and stars, with sizes ranging from 1 – 100 nm. They are produced as a suspension – the particles are suspended in a solvent, most often water.

Unique Optical Properties

One of the most useful optical properties of GNPs is that they change color readily, depending on their size, shape, and charge. This makes them, among other things, excellent labels for colorimetric detection of biomolecules.

These optical properties derive from an effect called surface plasmon resonance. Like all metals, gold contains free-moving electrons. When light hits the surface of a nanoparticle, these free electrons interact with the electric fields of the light rays and produce oscillations of charge that resonate with the wavelength of visible light.

The result is that GNPs absorb and reflect light at certain wavelengths, depending on their size, shape and surface chemistry.

For example, small (around 30 nm) GNPs absorb light in the blue-green portion of the spectrum (around 450 nm) and reflect red light (around 700 nm), so they are a rich red color.

As particle size increases, solutions become pale blue or purple as the red light is absorbed and blue light is reflected, until most visible wavelengths are reflected, at which point the solution is translucent.


Binding Properties

Another key property of GNPs is that they bind strongly to a range of molecules. This means that they can be coated with all kinds of molecules, such as polymers or biological recognition compounds, and their surfaces are tailored for specific applications.

For example, by coating GNPs with antibodies that bind to specific biomarkers, then measuring how the nanoparticles absorb light, the technology could be used to diagnose cancers and infectious agents.

Biomedical Applications

GNPs are ideally suited for biomedical research because they are biologically inert and generally considered to be non-toxic. There are four main areas of focus: medical imaging, diagnosis, drug delivery and targeted killing of cells.


Gold is a popular choice for diagnostics because it binds strongly to short, single strands of RNA or DNA (oligonucleotides) and changes color easily. By coating GNPs with oligonucleotides, they can be used to capture and identify genetic sequences that can be linked to molecules such as bacteria. Gold nanoparticles are also common in lateral flow immunoassays, a common household example being the home pregnancy test.

Drug Delivery

Because it is easy to attach molecules to gold, the particles can act as drug delivery vehicles, carrying drugs inside tumors, for example. Nanoparticles get trapped in the porous network of blood vessels that feed a tumor and accumulate there. When light shines on them, they absorb near-infrared wavelengths that pass through tissue without causing harm and start generating heat. This heat can kill cancer cells or release drugs from carriers.

Another approach is to build scaffolds out of GNPs and then arrange DNA or RNA around them (called spherical nucleic acids, or SNAs). They pass easily through the skin’s top layer – offering the potential for treatments for melanoma and other skin conditions – and are also able to cross the blood–brain barrier, so they could be used to target brain tumor cells.

Electronics, Food Science and Other Applications

Apart from life sciences, GNPs can be used in many other areas. These include in electronics as conductors and connectors in products such as printable inks and electronic chips; and in a variety of sensors. For example, a colorimetric sensor based on gold nanoparticles can identify if foods have started to go off

Other methods, such as surface enhanced Raman spectroscopy, rely on gold nanoparticles as substrates to enable the measurement of vibrational energies of chemical bonds. This technique could be used to detect pollutants and other molecules.

Although gold in bulk is a poor catalyst, it’s a different story for GNPs, which are proving to be important catalysts in fundamental research, in green chemistry where room temperature conversion of biomass and pollutants are crucial, and for fuel cell applications.

For example, GNPs coated onto semiconductor metal oxides catalyze the oxidation of carbon monoxide at relatively low temperatures. In fact, gold catalysts can promote many reactions, at lower temperatures and with higher selectivity than other metal catalysts.

Other examples include the selective oxidation of propylene, alcohols and polyols; selective hydrogenation; and hydrochlorination.


Suppliers for the Life Sciences Industry

There are many companies operating globally to serve the life sciences market. These include Cytodiagnostics, Sigma-Aldrich, BBI Solutions and Nanosphere.

Sigma-Aldrich, in conjunction with Cytodiagnostics, a biotech company based in Ontario, Canada, offers a broad portfolio of gold nanoparticles geared specifically for high-tech applications within life science and materials science. GNPs are available in sizes ranging from 5 – 400 nm in diameter with numerous surface functionalities in a variety of solvent compositions.

While spherical gold nanoparticles are traditionally made using reducing agents such as sodium citrate or sodium borohydride, Cytodiagnostics has a propriety process and formulation to prepare highly spherical gold nanoparticles, without harsh reducing agents. They claim that their proprietary protocols produce particles with uniform shapes and narrow size distributions.

The UK company BBI Solutions offers a range of particle sizes from 2 – 250 nm for a range of applications. BBI says its unique manufacturing technique allows the production of large batches of gold to a high level of reproducibility of size, dispersion, and shape. It claims its gold manufacturing technique guarantees: consistency; high stability; scalability; and quality.

US company Nanosphere, now part of Luminex Corporation, has developed a detector called Verigene based on GNPs coated with oligonucleotides to identify a dozen bacteria known to cause infection. In some cases, it can do this in 2 – 3 hours. Delivery of this time-critical information enables clinicians to provide targeted patient care more quickly than waiting for the results of cultured samples. Verigene is designed to target infections in the bloodstream, respiratory tract, and gastrointestinal tract.

The Future for Life Sciences Applications

Cancer therapy continues to be a major area of interest. An array of approaches are under investigation. These include delivering cancer medication, such as tumour necrosis factor, using GNPs (AstraZeneca/CytImmune); developing SNAs to pass from the bloodstream into the brain to treat brain tumours (AuraSense Therapeutics) and other solid tumours; coating glass shells with GNPs to improve the aim of lasers used to image and zap tumours (Nanospectra Biosciences).

These nanoshells could also serve as a delivery vector for gene silencing (when a gene is switched off). They can carry specific strands of DNA oligonucleotides or RNA molecules that are released when they are exposed to ultraviolet light, and turn off expression of a gene.

Much work continues to focus on diagnostics. Examples include GNP strip tests to detect certain heart attacks by identifying cardiac troponin I (cTn-I), found at several thousand times higher in patients experiencing myocardial infarctions (New York University Polytechnic School of Engineering); flu tests consisting of GNPs coated with antibodies that bind to specific strains of the flu virus (University of Georgia); and a new device that can spot the volatile organic compounds in exhaled breaths of patients with lung cancer (University of Colorado).

References and Further Reading

Gold Nanoparticles: Properties and Applications

Gold Nanoparticle Products

Gold Nanoparticles


Biomedicine: The New Gold Standard

Targeted Photodynamic Therapy of Breast Cancer Cells Using Antibody-phthalocyanine-gold Nanoparticle Conjugates

Gold Nanoparticles Market Size to Exceed USD 8 Billion by 2022

Graphene and its derivatives represent an exciting area of chemical discovery. With it’s range of exciting properties graphene based technology has the potential to transform our lives.

Graphene oxide membranes have been receiving attention for their extremely powerful separation abilities and the ease at which it can be modified, allowing for membrane permittivity to be fine-tuned. These membranes show the potential to be used for water purification, ‘green’ gas purification and greenhouse gas capture.

AZoNano spoke to Dr. Yang Su, of the University of Manchester’s prestigious National Graphene Institute, about the work he, and the rest of the team he is part of,  are conducting on these revolutionary membranes.

Why is graphene oxide a powerful candidate for use in next-generation membranes?

Next-generation membranes need to be highly selective, with a high permeability to a select few molecules, whilst also being inexpensive and stable enough for wide use. Graphene oxide shows the potential to be strong in all of these areas.

This is because the physical structure of graphene oxide sheets lends itself easily to being used as a membrane.

The structure of graphene oxide (GO). GO has oxidative ‘defects’ which break the perfect strucutre of graphene. Whilst this means GO is not as conductive as graphene the holes resulting from these defects make it perfect for use in membrane technology.

There are numerous pores inside membranes. It is the shape and size of these pores that defines the selectivity and permittivity of a membrane. Whereas the identity of the materials used to construct the membrane and the way in which it is processed determines its stability and cost.

Graphene oxide (GO) membranes consist of many layers of two dimensional graphene oxide layers stacked on top of each other to give a laminate of two dimensional GO sheets. These stacked sheets have interconnected channels running through them which act as the membranes pores.

The pores are uniform in size and only 0.9 nm in width. This small width means the membrane is highly selective as only ions and molecules smaller than 0.9 nm can permeate through. Any ions or molecules larger than 0.9 nm are prevented from passing through the membrane by a process called physical extrusion.

The channels inside the GO membrane can be modified with different methods based on what type of membrane is required. Modifying the membrane channels allows membrane permeability to be fine-tuned meaning certain compounds and ions can be selected in such a way that the membrane is highly permeable to them.

Additionally, unlike polymer membranes, GO membranes are more chemically inert, which means they have a longer service lifetime.

Graphene oxide is not as expensive as pure graphene and it can, in fact, be made easily using only graphite powder and some inexpensive chemistry which could even be carried out at home. (though I wouldn’t recommend it!)

This high selectivity coupled with a low cost and long operational lifetime is why there is so much interest in GO advanced membrane technology.

An image of multilayer graphene. Sheets in GO membranes are organised in a similar fashion. Layered one over another to give a laminate. Shutterstock | Bessarab

Can unadulterated, pure graphene be used for this purpose?

Pure graphene is highly impermeable. Graphene will occasionally be permeable to very small particles such as protons (one of the components of an atomic nucleus) but this is only under very specific conditions that you wouldn’t find outside of a lab.

Any matter larger than a proton, such as liquids and gases, will be completely impermeable to graphene. However, this impermeability has its own uses – for example graphene would work very well as a barrier or protective membrane.

As pure graphene is completely defect free there are no gaps in its structure making it completely impervious to all but the smallest of particles. Shutterstock | ktsdesign

What molecules and liquids are GO membranes capable of separating?

The unique pore structure of GO membrane provides a good platform for us to play with. By changing the structure of the membrane we can adjust the membranes permeability with respect to different molecules.

Depending on the membrane structure they can be used for gas separation, such as hydrogen purification, CO2 capture, or gas drying by removing water.

The GO membranes can also be used for the separation of aqueous mixtures, such as in the dehydration and purification of organic solvents. This technology has the potential to be used to separate certain solute/ions from solvents, which could potentially be used for water purification.

How can the membrane separation properties be modified? Can the membrane be functionalised or the pore size controlled in other ways?

The membrane separation properties can be modified using many different methods with the main methods being chemical functionalization and physical pore size control.

Attaching external molecules to the sheets by chemical functionalization can be used to expand the pore sizes. This results in faster transport through the membranes and different selectivities.

In contrast, our recent results show that by removing oxygen atoms from GO sheets we could induce the channels to collapse. This type of GO membrane could be used as a barrier or protective coating for the packaging industry.

How do you see this technology impacting the real world?

Due to its amazing separation properties we expect this technology to have a huge impact in the fields of energy reduction and environmental conservation.

For example, this technology could be used for the dehydration and purification of biofuels. Currently water is produced as a side product when biofuels are produced. This water damages the biofuel yield and the final product quality, and its removal is difficult. Our GO membranes could help solve this problem.

GO membranes also have the potential to be used for portable water purifiers. The small pore size of the membranes means all of the bacteria present in dirty water, and most of the other impurities, will be sieved out with only pure water passing through. This technology would be hugely useful in the developing world. The membranes also show promise for use in water desalination, but we’re not quite there yet.

The membranes also have the ability to separate gases, meaning in the future they could be used to control greenhouse gas emissions and to purify hydrogen related clean energy gases.

GO membrane technology could assist in the production and purification of clean biofuels. 

Do you think graphene oxide membranes have the potential to be used for large scale water filtration or do you believe this would be impractical?

The membrane technology that we are developing could definitely be used for large scale water filtration.

Firstly, graphene oxide can be manufactured on a large scale meaning the materials are readily available. Secondly, the membranes are produced with little difficulty, even simple membranes formed by evaporating water from a GO suspension results in a GO membrane that performs well.

Finally, and most importantly, the membranes already show amazing properties for sieving impurities from water. Of course, at our current stage, we still need to work hard to address several issues on its practical applications, but our research team are working on this and I’m confident we will get there.

How does your research on graphene membranes fit into the wider picture, with the other research being undertaken at the National Graphene Institute?

The National Graphene Institute at the University of Manchester

When do you expect this technology to become widely available? What obstacles must be overcome before this happens?

We don’t have a detailed timeline yet. At our current stage, among a lot of possible applications, we are assessing them for one or two applications which could be realized on a large scale.

Our main obstacle is that we need more industrial partners to fill the gap between the lab experiments and pilot scale productions, we then could conduct application-oriented research to finalize the end products.

Castor oil

Oils, including olive, castor and coconut, are rich in vitamins, minerals and antioxidants. This means that they not only moisturize, hydrate and replenish, but in terms of your skin, they will also offer anti-aging properties. From avocado to sweet almond, each oil offers their own unique benefits — but today, let’s focus on castor oil.

11 ways to use castor oil for better skin and hair

Although fairly common, castor oil is not generally as well known as say olive oil. High in vitamin E, minerals, proteins and even beneficial fatty acids, castor oil is great for both your skin and hair. If you have a bottle lying around your home, it’s time to put it to good use — here’s how.

1. Enhance the natural look of your hair

Castor oil can enhance the look and feel of your hair, making it look both thicker and richer. Locking in moisture, this oil is what’s known as a humectant, making each strand of hair look that much healthier. After you shower and towel dry your hair, apply a small amount of slightly warmed castor oil, working it into the strands of your hair.

2. Cleanse your skin

Whether you’d like to wash off makeup or benefit from a deep clean, castor oil can help cleanse your pores. In order to benefit from an effective deep cleanse, mix a small amount of castor oil with jojoba oil (1:1 ratio). Massage these oils into your face gently, covering the entire surface of your face. After 10 minutes, wash your face with a warm cloth. This steaming process will help remove excess oil, dirt and other pore-clogging material.

3. Target fungal skin conditions

Whether you’re suffering from athlete’s foot or ringworm, castor oil is rich in a biochemical known as undecylenic acid — which helps target fungal growth. It’s recommended that you mix castor or with coconut oil, applying it too problematic areas repeatedly until cured.

4. Reduce the appearance of stretch marks

There are a number of reasons why one may suffer from stretch marks, including the effects of puberty and pregnancy. Castor oil is high in what’s known as ricinoleic acid, a fatty acid that helps target the appearance of stretch marks. Massage castor oil into the desired area and wrap with a cotton cloth, allowing the oil to penetrate the skin for 15 to 20 minutes. Repeat on a regular basis for three to four weeks.

5. Fade scars

If you have scars from when you had chickenpox or acne,, castor oil can help you reduce their appearance. Due to its high fatty acid content, castor oil will penetrate through the epidermal layer,helping to heal the scar tissue by promoting new skin cell growth. Apply before bed, massaging the oil deep into the skin. Leave the oil on overnight and wash it off the next morning.

6. Treat acne

Speaking of scars from acne, why not treat acne before it has a chance to scar your skin? Once again, the fatty acid known as ricinoleic acid helps fight acne-causing bacteria. This is especially effective for cystic acne, which is generally more severe. Wash your face, then apply a few drops of castor oil, rubbing it into the affected area. Wash an hour later, or leave on overnight before rinsing.

7. Use as all-natural massage oil

Although you can treat many surface conditions with castor oil, the benefits are more than skin deep. When using as a massage oil, you can help enhance circulation and target sore, achy muscles and joints. Your scalp is also a great area to massage, helping target problematic dandruff. Just remember, this oil can stain your clothes. Wear old clothing after applying it to your body.

8. Balance scalp pH

Ricinoleic acid has been found to potentially help balance scalp pH, replenishing natural oils and promoting positive hair health. In turn, this can help undo some of the damage that has been caused by harsh hair products. When the pH of your scalp is either too alkaline or too acidic, this can lead to bacterial or fungal issues, an itching scalp and dandruff.

9. Supports hair growth

There have been many cases where individuals swear by castor oil for hair growth, helping to enhance the growth rate. When applied to the scalp, this oil penetrates deep into the pores of your hair follicles, providing nourishment. Work around three tablespoons of castor oil into your scalp. Leave it on for 20 minutes before washing it out with an all-natural shampoo.

10. Soothe bug bites and stings

When you want to soothe an insect bite or sting, castor oil can help reduce itching and encourage more rapid healing. Offering both anti-inflammatory and antibacterial properties, castor oil will help soothe and heal when applied to itchy bites. Simply apply a small amount to the affected area and repeat throughout the day.

11. Combat lines and wrinkles

The fatty acids found in castor oil will penetrate deep into the skin, stimulating the production of elastin and collagen. It will also target dark bags and the appearance of crow’s feet. Since the skin around your eyes is so delicate, it’s more prone to damage. To apply, make sure you cleanse your skin, applying a small amount of castor oil around the edges of your eyes and forehead.

Castor oil is not only effective, it’s cost-effective. It helps you benefit from a wide range of uses with just one bottle. Whether you want to brighten the look of your hair or combat eczema, every home should have a bottle of castor oil in the medicine cabinet. It’s time to re-think not only what you put in your body, but what you put on your body as well.

BPA FREE…….????

In 2008, the possible health risks of Bisphenol A (BPA) — a common chemical in plastic — made headlines. Parents were alarmed, pediatricians flooded with questions, and stores quickly sold-out of BPA-free bottles and sippy cups.

Where do things stand now? Have plastic manufacturers changed their practices? How careful does a parent need to be when it comes to plastics and BPA? Here’s the latest information we have about possible BPA risks.

BPA Basics

BPA is a chemical that has been used to harden plastics for more than 40 years. It’s everywhere. It’s in medical devices, compact discs, dental sealants, water bottles, the lining of canned foods and drinks, and many other pro

More than 90% of us have BPA in our bodies right now. We get most of it by eating foods that have been in containers made with BPA. It’s also possible to pick up BPA through air, dust, and water.

BPA was common in baby bottles, sippy cups, baby formula cans, and other products for babies and young children. Controversy changed that. Now, the six major companies that make baby bottles and cups for infants have stopped using BPA in the products they sell in the U.S. Many manufacturers of infant formula have stopped using BPA in their cans, as well.

According to the U.S. Department of Health, toys generally don’t contain BPA. While the hard outer shields of some pacifiers do have BPA, the nipple that the baby sucks on does not.

BPA Risks

What does BPA do to us? We still don’t really know, since we don’t have definitive studies of its effects in people yet. The U.S. Food and Drug Administration used to say that BPA was safe. But in 2010 the agency altered its position. The FDA maintains that studies using standardized toxicity tests have shown BPA to be safe at the current low levels of human exposure. But based on other evidence — largely from animal studies — the FDA expressed “some concern” about the potential effects of BPA on the brain, behavior, and prostate glands in fetuses, infants, and young children.

Bisphenol A is used primarily to make plastics, and products using bisphenol A-based plastics have been in commercial use since 1957.At least 3.6 million tonnes (8 billion pounds) of BPA are used by manufacturers yearly. It is a key monomer in production of epoxyresins and in the most common form of polycarbonate plastic. Bisphenol A and phosgene react to give polycarbonate under biphasic conditions; the hydrochloric acid is scavenged with aqueous base:


Diphenyl carbonate may be used in place of phosgene. Phenol is eliminated instead of hydrochloric acid. This transesterification process avoids the toxicity and handling of phosgene

Nobel Prize in Chemistry 2016

5 October 2016

Stoddart’s study showed that molecular machines could influence objects many magnitudes larger than themselves, but looking beyond switches, scientists have since moved on to designing more complex motor-based systems.


The rotaxane made by Stoddart’s group could bend gold foil: the macrocycles (blue) move closer together when oxidised

The Royal Swedish Academy of Sciences has decided to award the Nobel Prize in Chemistry 2016 to

Jean-Pierre Sauvage
University of Strasbourg, France

Sir J. Fraser Stoddart
Northwestern University, Evanston, IL, USA


Bernard L. Feringa
University of Groningen, the Netherlands

“for the design and synthesis of molecular machines”

They developed the world’s smallest machines

A tiny lift, artificial muscles and miniscule motors. The Nobel Prize in Chemistry 2016 is awarded to Jean-Pierre Sauvage, Sir J. Fraser Stoddart and Bernard L. Feringa for their design and production of molecular machines. They have developed molecules with controllable movements, which can perform a task when energy is added.

The development of computing demonstrates how the miniaturisation of technology can lead to a revolution. The 2016 Nobel Laureates in Chemistry have miniaturised machines and taken chemistry to a new dimension.

The first step towards a molecular machine was taken by Jean-Pierre Sauvage in 1983, when he succeeded in linking two ring-shaped molecules together to form a chain, called a catenane. Normally, molecules are joined by strong covalent bonds in which the atoms share electrons, but in the chain they were instead linked by a freer mechanical bond. For a machine to be able to perform a task it must consist of parts that can move relative to each other. The two interlocked rings fulfilled exactly this requirement.

The second step was taken by Fraser Stoddart in 1991, when he developed arotaxane. He threaded a molecular ring onto a thin molecular axle and demonstrated that the ring was able to move along the axle. Among his developments based on rotaxanes are a molecular lift, a molecular muscle and a molecule-based computer chip.

Bernard Feringa was the first person to develop a molecular motor; in 1999 he got a molecular rotor blade to spin continually in the same direction. Using molecular motors, he has rotated a glass cylinder that is 10,000 times bigger than the motor and also designed a nanocar.

2016’s Nobel Laureates in Chemistry have taken molecular systems out of equilibrium’s stalemate and into energy-filled states in which their movements can be controlled. In terms of development, the molecular motor is at the same stage as the electric motor was in the 1830s, when scientists displayed various spinning cranks and wheels, unaware that they would lead to electric trains, washing machines, fans and food processors. Molecular machines will most likely be used in the development of things such as new materials, sensors and energy storage systems.


 – Think of melatonin as your biological clock. This hormone is responsible for the way you feel throughout the day as far as alertness is concerned. All those drowsy feelings? Blame the melatonin.

Serotonin – This is the one you can blame for PMS and your moody teenager. Serotonin controls your mood, appetite, and your sleep cycles.

Thyroxin – A form of thyroid hormone, thyroxin increases the rate of your metabolism and also affects protein synthesis, which is the process that cells go through to build protein.

Epinephrine – This is one that you have most likely heard of; it’s also called adrenaline. Among a whole list of other things, epinephrine is responsible for what is known as the, “fight or flight” response. This is the hormone that tells you when to fight and when it’s best to run. Some of the bodily responses demonstrated when this hormone kicks in are dilated pupils, increased heart rate, and tensing of the muscles.

Norepinephrine – Also called noradrenaline, this hormone controls the heart and blood pressure. Norepinephrine also contributes to the control of sleep, arousal, and emotions. Obvious effects take place when there is too much or too little of this hormone. Too much gives you an anxious feeling while too little can leave you feeling depressed or sedated.

Dopamine – This controls the heart rate and also assists in perception; deciphering what is real and what is not.

Antimullerian Hormone – An inhibitor for the release of prolactin, the protein responsible mainly for lactation.

Adiponectin – This is a protein hormone, it regulates metabolic processes such as the regulation of glucose.

Adrenocorticotropic Hormone – This assists in synthesizing corticosteroids, which are responsible for stress response, blood electrolyte levels, and other physiologic systems.

Angiotensinogen – Responsible for the narrowing of blood vessels; a process known as vasoconstriction.

Antidiuretic Hormone – This hormone is also known by other names, but it is mainly responsible for retaining water within the kidneys.

Atrial Natriuretic Peptide – A peptide hormone secreted by the cells of the heart and other muscles, it’s mostly involved with the control of water, sodium, potassium, and fat within the body.

Calcitonin – Aids in constructing bone and reducing blood calcium.

Cholecystokinin – Aids in the release of digestive enzymes for the pancreas and acts as an appetite suppressant.

Corticotrophin-Releasing Hormone – Releases cortisol in response to stress.

Erythropoietin – Stimulates the production of erythrocytes, which are blood cells responsible for delivering oxygen.

Follicle-Stimulating Hormone – Stimulates the follicles within the sex organs of both males and females.

Gastrin – Secretes gastric acid.

Ghrelin – Hunger stimulant as well as aiding in the secretion of the growth hormone.

Glucagon – Helps to increase the blood glucose level.

Growth Hormone-Releasing Hormone – As its name clearly implies, this hormone releases the growth hormone.

Human Chorionic Gonadotropin – Keeps the immune system from attacking a forming embryo during pregnancy.

Growth Hormone – Helps to stimulate growth and the reproduction of cells.

Insulin – Responsible for several anabolic effects, primarily glucose intake.

Insulin-Like Growth Factor – Has the same effects as insulin while also regulating the growth and development of cells.

Leptin – Slows down the appetite while simultaneously speeding up metabolism.

Luteinizing Hormone – Aids ovulation in women and testosterone production in men.

Melanocyte Stimulating Hormone – Produce melanocytes, which are responsible for the pigment in skin and hair.

Orexin – Increases the appetite while also increasing your alertness and energy levels.

Oxytocin – A hormone that plays a major role in reproduction, it aids in orgasm and is also responsible for the release of breast milk.

Parathyroid Hormone – Among other functions, this hormone is mainly responsible for the activation of Vitamin D.

Prolactin – A major contributor in sexual satisfaction and the production of breast milk.

Secretin – Inhibits gastric acid production.

Aldosterone – Mainly responsible for absorbing sodium in the kidneys to increase the volume of blood within the body.

Testosterone – The major male hormone, testosterone is responsible for sex drive, development of the sex organs, and the changes that take place during puberty.

Androstenedione – Essentially estrogen.

Estradiol – In males, this hormone is responsible for preventing what is basically known as cell death of the germ cells. In females, this hormone is in overdrive. Among other things, estradiol accelerates height and metabolism, maintains the blood vessels and skin, aids in water retention, and even aids in hormone-sensitive cancers.

Progesterone – A major contributor to the body’s support of pregnancy.

Lipotropin – Stimulates the production of pigment by aiding in melanin production.

Brain natriuretic peptide – Aids in reducing blood pressure.

Histamine – A hormone based in the stomach, histamine aids in the secreting of gastric acid.

Endothelin – Controls muscle contractions within the stomach.

Enkephalin – Simply a pain regulator.


There are twenty-five methods to purify water, divided into four categories: separation, filtration, chemicals, oxidation.
There are five types of contaminants that are found in water: particulates, bacteria, minerals, chemicals, and pharmaceuticals. Methods to remove these elements range from simple and inexpensive to elaborate and costly. Often to achieve purely potable water, several technologies must be combined in a particular sequence. Listed here are general brief descriptions of the twenty-five methods to purify water.


SEDIMENTATION gravitationally settles heavy suspended material.
BOILING WATER for 15 to 20 minutes kills 99.9% of all living things and vaporizes most chemicals.  Minerals, metals, solids and the contamination from the cooking container become more concentrated.
DISTILLATION boils and recondenses the water, but many chemicals vaporize and recondense in concentration in the output water.  It is also expensive to boil & cool water.
ULTRAVIOLET LIGHT is a good bactericide, but has no residual kill, and works only in clearly filtered water.   Still in its infancy stage is a new technology involving super white light.


CHLORINE is common, cheap, but extremely toxic.  It does not decrease physical or chemical contamination, it does increase colesterol formations, is a carcinogen, and causes heart disease.
BROMINE, used in pools and spas, doesn’t smell or taste as bad and doesn’t kill bacteria very well.
IODINE is not practical, and is mostly used by campers.
HYDROGEN PEROXIDE kills bacteria with oxygen, is chemically made and is very toxic.  It is used in emergencies.
SILVER is an effective bactericide but a cumulative poison which concentrates and doesn’t evaporate.
NONTOXIC ORGANIC ACIDS should be used with caution in large water plants only.
LIME AND MILD ALKALINE AGENTS should also be used with caution only by large water plants, or only for laundry.
NEUTRALIZING CHEMICALS react with the unwanted chemicals and produce outgases and a sediment, but levels of need vary.
COAGULATION-FLOCCULATION adds chemicals which lump together suspended particles for filtration or separation.
ION EXCHANGE exchanges sodium from salt for calcium or magnesium, using either glauconite (greensand), precipitated synthetic organic resins, or gel zeolite, thus softening the water.  Minerals, metals, chemicals or odors are not affected, and the water is salty to drink.


SLOW SAND of 1 cubic meter passes about 2 liters/min, and does a limited bacteria removal.
PRESSURE SAND of 1 cubic meter passes about 40gpm and must be backwashed daily.
DIATOMACEOUS EARTH removes small suspended particles at high  flow rates, must be daily backwashed and is expensive.
POROUS STONE/CERAMIC filters are small but expensive, and do not effect chemicals, bacteria or odors.
PAPER or CLOTH filters are disposable and filter to one micron, but do not have much capacity.
-COMPRESSED CHARCOAL/CARBON BLOCK is the best type of charcoal  filter, can remove chemicals and lead, but is easily clogged,  so  should be used with a sediment prefilter.
-GRANULAR CHARCOAL is cheaper, but water can flow around the  granules without being treated.
-POWDERED CHARCOAL is a very fine dust useful for spot cleaning  larger bodies of water, but is messy and can pass through some filters and be consumed.
REVERSE OSMOSIS uses a membrane with microscopic holes that require 4 to 8 times the volume of water processed to wash it in order to remove minerals and salt, but not necessarily chemicals and bacteria.
ENZYMES &BACTERIA combined can remove contaminants, reduce sludge, and even digest oil. See recent article on enzymes & bacteria.
PLANTS There are numerous plants, animals and organisms that are quite effective in filtering water.


AERATION sprays water into the air to raise the oxygen content, to break down odors, and to balance the dissolved gases.  However, it takes space, is expensive, and picks up contaminants from the air.
OZONE is a very good bactericide, using highly charged oxygen molecules to kill microorganisms on contact, and to ozidize and flocculate iron, manganese and other dissolved minerals for post-filtration and backwashing.
ELECTRONIC PURIFICATION and DISSOLVED OXYGEN GENERATION creates super oxygenated water in a dissolved state that lowers the surface tension of the water and effectively treats all three types of contamination: physical, chemical and biological.

Image result for water purification