Electronic tongue can tell if your honey is adulterated


Image: Electronic tongue can tell if your honey is adulterated

In response to all of the fake honey that have been infiltrating the market for the longest time, Spanish researchers have come up with an electronic tongue that can tell the difference. An article in Alpha Galileo reported that the device is inexpensive, is quick to pick up on the presence of adulterated honey, and can even tell you how much fake sweetener is present.

Current methods of determining the authenticity of a honey product requires days of thoroughly analyzing the sample. In comparison, the new device takes just an hour to figure out if the honey is truly pure or has been diluted by scammers.

The Polytechnic University of Valencia (UPV) researchers demonstrated the capability of their new device in a test. Their results showed that the electronic tongue can tell between pure honey and the syrups and sugar molasses that are commonly used to dilute the profitable product.

“This leads to noticeable losses for the honey bee sector,” remarked Lara Sobrino. A researcher who works at UPV’s Developmental Food Engineering Institute, she added that the scam not only violates EU laws, it also causes consumers to lose faith in the honey bee sector, which will hurt the industry in the long run. (Related: Understanding the differences between sugars: white, brown, raw, molasses, honey, agave.)

This electronic tongue can tell genuine honey from watered-down fakes

The official name of the device is the “electronic voltammetric tongue.” Its creators described it as an effective and affordable alternative to the bulkier gear used by most scam hunters. It will not only spot the presence of syrups in real honey, but will also determine the percentage of the product that has been compromised.

Mother Nature’s micronutrient secret: Organic Broccoli Sprout Capsules now available, delivering 280mg of high-density nutrition, including the extraordinary “sulforaphane” and “glucosinolate” nutrients found only in cruciferous healing foods. Every lot laboratory tested. See availability here.

In the test, the device compared pure honey from heather, orange blossom, and sunflower with dietary syrups made from barley, brown rice, and corn. It successfully differentiated the true honey from the syrups used to fake them.

The electronic tongue is able to clean itself very thoroughly. This reduces the chances of erroneous analysis caused by leftovers from the previous sample.

Finally, it enables statistical analysis of the resulting information. The combination allowed the device to detect any symptoms of fraud in a product.

“Out work offers a pioneering analytical technique that makes it possible to find out quickly and reliably the honey’s authenticity,” said Juan Soto, another UPV researcher from the university’s Molecular Recognition and Technological Development Institute who worked alongside Sobrino. He believed that the electronic tongue offers an answer to suspicions about the purity of honey products.

New device can improve the efficiency of existing methods for hunting fake honey

Members of the honey bee sector can use the UPV detector to ensure the quality of their products, thereby restoring the faith of their customers. They will also be able to catch scammers who are taking advantage of the confusion to make big bucks off gullible consumers.

“If there is the suspicion that a honey could be adulterated, our system detects the symptoms reliably,” Soto said. He also noted that their electronic tongue will work best alongside other detectors as a first line of defense against fakes.

Magnetic resonance detectors are slower and much more expensive than the UPV device. But they can perform in-depth analyses of samples that are beyond the specialized capabilities of the electronic tongue.

Soto believes that his team’s device can screen suspicious samples first. If it catches any fake honey, it can pass the offender over to another identification technique for confirmation.

Developed a taste for the latest news about honey? You can satisfy your craving for more stories at Bees.news.

Sources include:

AlphaGalileo.org

ScienceDirect.com

Electronic tongue can tell if your honey is adulterated


Image: Electronic tongue can tell if your honey is adulterated

In response to all of the fake honey that have been infiltrating the market for the longest time, Spanish researchers have come up with an electronic tongue that can tell the difference. An article in Alpha Galileo reported that the device is inexpensive, is quick to pick up on the presence of adulterated honey, and can even tell you how much fake sweetener is present.

Current methods of determining the authenticity of a honey product requires days of thoroughly analyzing the sample. In comparison, the new device takes just an hour to figure out if the honey is truly pure or has been diluted by scammers.

The Polytechnic University of Valencia (UPV) researchers demonstrated the capability of their new device in a test. Their results showed that the electronic tongue can tell between pure honey and the syrups and sugar molasses that are commonly used to dilute the profitable product.

“This leads to noticeable losses for the honey bee sector,” remarked Lara Sobrino. A researcher who works at UPV’s Developmental Food Engineering Institute, she added that the scam not only violates EU laws, it also causes consumers to lose faith in the honey bee sector, which will hurt the industry in the long run. (Related: Understanding the differences between sugars: white, brown, raw, molasses, honey, agave.)

This electronic tongue can tell genuine honey from watered-down fakes

The official name of the device is the “electronic voltammetric tongue.” Its creators described it as an effective and affordable alternative to the bulkier gear used by most scam hunters. It will not only spot the presence of syrups in real honey, but will also determine the percentage of the product that has been compromised.

Mother Nature’s micronutrient secret: Organic Broccoli Sprout Capsules now available, delivering 280mg of high-density nutrition, including the extraordinary “sulforaphane” and “glucosinolate” nutrients found only in cruciferous healing foods. Every lot laboratory tested. See availability here.

In the test, the device compared pure honey from heather, orange blossom, and sunflower with dietary syrups made from barley, brown rice, and corn. It successfully differentiated the true honey from the syrups used to fake them.

The electronic tongue is able to clean itself very thoroughly. This reduces the chances of erroneous analysis caused by leftovers from the previous sample.

Finally, it enables statistical analysis of the resulting information. The combination allowed the device to detect any symptoms of fraud in a product.

“Out work offers a pioneering analytical technique that makes it possible to find out quickly and reliably the honey’s authenticity,” said Juan Soto, another UPV researcher from the university’s Molecular Recognition and Technological Development Institute who worked alongside Sobrino. He believed that the electronic tongue offers an answer to suspicions about the purity of honey products.

New device can improve the efficiency of existing methods for hunting fake honey

Members of the honey bee sector can use the UPV detector to ensure the quality of their products, thereby restoring the faith of their customers. They will also be able to catch scammers who are taking advantage of the confusion to make big bucks off gullible consumers.

“If there is the suspicion that a honey could be adulterated, our system detects the symptoms reliably,” Soto said. He also noted that their electronic tongue will work best alongside other detectors as a first line of defense against fakes.

Magnetic resonance detectors are slower and much more expensive than the UPV device. But they can perform in-depth analyses of samples that are beyond the specialized capabilities of the electronic tongue.

Soto believes that his team’s device can screen suspicious samples first. If it catches any fake honey, it can pass the offender over to another identification technique for confirmation.

Developed a taste for the latest news about honey? You can satisfy your craving for more stories at Bees.news.

Sources include:

AlphaGalileo.org

ScienceDirect.com

The 25 Biggest Scientific Breakthroughs of 2017


Every week in 2017 seemed to bring new, objectively bad news about environmental degradation, government officials being awful, or video gamesbeing ruined by microtransactions. But it wasn’t all bad news: Very exciting and groundbreaking research was added to the scientific literature this year, reminding us that not everything is moving backward.

The 25 studies below, representing the biggest breakthroughs of the year, represent a wide and eclectic range of research areas. Let these snippets from Inverse’s interviews with researchers offer a sense of just how many scientific fields strode forward in 2017:

  • “It’s a terrible way to define different populations,” a geneticist studying skin color said.
  • “Best-case scenario, some of the advertising is true. Worst-case scenario: very little to none of the advertising is true and people may actually get hurt,” said a psychologist about the problems with mindfulness.
  • “What we showed is that diarrhea is actually really good for you,” said a scientist researching diarrhea.

Without further ado, here are the studies that rocked the science world this year, presented in order of popularity among our readers, though not necessarily importance:

25. Neanderthals Never Would Have Outlived Us

Humans still contain a small percentage of Neanderthal DNA. Even though we know that humans and Neanderthals overlapped for about 15,000 years, scientists aren’t sure how our ancient cousins died out. They’re pretty sure that Neanderthals would have been replaced by humans no matter what. Computer modeling shows that humans migrating out of Africa would have replaced Neanderthals, whether or not they died out from other factors. But while they lived together, Neanderthals left their genetic legacy imprinted in our DNA.

24. Magic Mushrooms Can Help with Depression

Scientists put tripping patients into fMRI machines to observe what their brains did under the influence of psilocybin, the active ingredient in hallucinogenic, “magic,” mushrooms. They found that patients with depression described feeling “reset” after a trip, and brain scans supported this conclusion. Patients who reported feeling better also showed reduced blood flow to parts of the brain associated with depressive symptoms.

23. Teeth From 9.7 Million Years Ago Could Rewrite Human History

Scientists found teeth in Germany that they suspect come from hominins. They date back to before similar human ancestors arose in Africa, suggesting that we may need to rework the entire human evolutionary timeline. Whether it’s a product of convergent evolution or simply related species, these fossils raise more questions about human origins than they answer.

22. Eating Weed and Spicy Food Is Good for Your Gut

More good news from 2017! Researchers found that marijuana and spicy food can ease inflammation in your digestive system, potentially paving the way for new treatments for Type 1 diabetes, colitis, and other gut issues. Capsaicin, the spicy stuff in chili peppers, makes your digestive system produce a type of cannabinoid that can offer protective benefits to your gastrointestinal tract, suggesting that edible marijuana could do the same thing. This is good news for lovers of spicy food and edibles.

21. Dogs Are Genetically Predisposed to Being Good Boys

It’s not all bad news for 2017: Scientists examining dog genetics found that dog genes predispose them to domestication and prosocial behavior. This study is the first to show why, on a molecular level, dogs are _so good). Interestingly, the scientists also found that the same genetic changes that led to domestication also seems to have made dogs less intelligent than wolves.

20. You’re More Likely to View Atheists as Serial Killers

Even though atheism has become more common in modern society, it turns out believing in something might make you seem less like a psychopath, according to a study published this year. People are more likely to believe that a killer in a hypothetical scenario is an atheist instead of a person of faith, according to research published this year. This finding even held true for atheists, perhaps suggesting some internalized stigma leading to unconscious bias. Even Mark Zuckerberg has taken note of this anti-atheist prejudice, announcing his faith a year ago.

19. Human-Pig Chimeras Have a “Safety Switch”

Scientists shocked the world when they announced they’d developed a human-pig chimera, bringing us a step closer to growing human organs inside pigs. But they also soothed our fears of a pig-man apocalypse when they assured us that there is a self-destruct mechanism for human stem cells that accidentally travel to the pig brains. It’s not even clear whether that would lead to enhanced consciousness, but if this safety switch works, we won’t have to worry about it.

18. Psychologists are Growing Skeptical of Mindfulness Practices

Mindfulness has become a pop psychology buzzword recently, and psychology professionals are concerned. Fifteen psychologists published a paper this year outlining their concerns that corporate seminars, meditation workshops, and the like are offering psychological benefits that are unproven while ignoring risks. After all, psychological health is not one-size-fits-all.

17. Even Occasional Drinks Can Affect Your Brain Health

We all know that drinking too much can cause chronic health problems, but a massive cohort study of British civil servants found that moderate drinking accelerates cognitive decline. Over 30 years of surveys and health check-ups, the participants who consumed 14 to 21 units of alcohol per week “had three times the odds of right sided hippocampal atrophy,” an early warning sign of Alzheimer’s disease. This is a serious buzzkill, since previous research has suggested that moderate drinking could have certain benefits for heart health. Following this cohort of research subjects further will reveal more about their health as they age.

16. Your Face Shows Signs of Class Boundaries

It’s sometimes easy to tell whether someone is wealthy based on their clothes, car, home, and other material things. But this year researchers found that social status may show in your face, too. This doesn’t mean that some people are genetically predisposed to be rich, but rather that being poor can impart subtle, lifelong mood symptoms that observers can see on your face even when you’re wearing a neutral expression. Worryingly, the researchers found that this judgment can impair hireability, which could perpetuate class boundaries.

15. Scientists Identified the Maximum Human Lifespan

Life extension advocates like to say that, with the right supplements and therapies, you’ll be able to live long enough to see science bring about immortality. But more conventional-thinking researchers say this isn’t so. They identified the maximum human lifespan as 115.7 years for women and 114.1 years for men. This area of research is still hotly debated, but the new findings fit pretty closely to what other groups have said.

14. A Supervolcano Could Go Off Way Sooner Than We Think

As if 2017 wasn’t bad enough, statisticians say we’re overdue for a supervolcano eruption. On the basis of geological records, a team of researchers estimated that cataclysmic supervolcano eruptions on Earth occur, on average, every 17,000 years. The last one happened 20 to 30 thousand years ago. You do the math.

13. Geneticists Discovered That Light Skin Variations Originated in Africa

Science has often been used in the service of justifying racism, but scientists shut down outdated notions of genetic differences among humans of different ethnic groups this year. Geneticists found that variants associated with light skin actually originated in Africa, not only disproving the backward notion that people with darker skin are less human, but also calling into question the notion that skin color can be associated with certain ethnic groups.

12. Scientists Find the Oldest Human Skeleton in the Americas

After re-examining a skeleton stolen from a submerged cave in Mexico, scientists determined that it may represent the oldest human remains ever found in the Americas. At 13,000 years old, the 80-percent-complete skeleton suggests that humans came to the Americas thousands of years before the people that were previously thought to be the first Americans.

11. Diarrhea Is Your Body’s Immune System Savior

Diarrhea sucks, but there’s actually a good reason for it. Mice infected with a mouse bacteria similar to E. coli exhibited changes in intestinal cells in a way that seemed to cause diarrhea. Scientists have long suspected that diarrhea was the body’s way of clearing out disease, but this study provided the first solid proof.

10. Redditors’ Dicks Match Up With Dick Size Desires

Many penis-havers worry about whether their penis size will match up with the preferences of penis-likers. In a study conducted by and among redditors, they found that penis sizes matched up pretty well with what their potential partners want. These findings fit with what academic researchers have found, but maybe this citizen science confirmation will be more digestible for redditors.

9. Porn Can Change Your Brain

People who watch a lot of pornography don’t necessarily have an addiction or a psychological condition. But neuroscientists have found that people who struggle with their porn use exhibit brain changes. They react more strongly to reward cues associated with porn, similar in some ways to gambling addicts. It’s not clear whether porn addiction is a real condition, though.

8. Scientists Send Data to and from Space Using Quantum Entanglement

Scientists in China transmitted a quantum state almost a thousand miles into space, much farther than had been done previously. This development brought scientists one step closer to the kind of technology that could enable quantum computing. Quantum entanglement is a burgeoning topic in physics that even Albert Einstein didn’t believe could exist.

7. Human Mini-Brain Organoids Raise Ethical Concerns

Scientists can grow miniature models of human organs, called organoids that allow them to perform research that would be unethical on living. But when scientists reported that human brain organoids grafted onto rat brains had begun to integrate, this raised ethical red flags. If a rat has a partially human brain, should we be doing science on it that we wouldn’t do on a human?

Alex Jones

6. Conspiracy Theorists Think Differently

European social psychologists have shed some light on what makes the nearly half of American conspiracy theorists different from the rest. They exhibit a phenomenon called illusory pattern perception, which makes them see patterns of danger where there is no danger. This is the first scientific evidence linking illusory pattern perception to belief in conspiracy theories.

5. Ancient Humans Knew How to Avoid Incest

We know that incest increases the chances of developing genetic diseases, but it turns out our early human ancestors knew about the risks of incest, too. Geneticists and archaeologists examining 34,000-year-old human remains from Russia found that four people buried together were no closer than second cousins, suggesting that even ancient humans made efforts to avoid inbreeding. Researchers say this probably means these early humans made a purposeful effort to mix outside their family groups, including some semblance of romance, as indicated by the jewelry included in their collective burial.

4. Scientists Discovered Our Black Hole Neighbors

Astronomers using NASA’s NuSTAR X-ray telescope found evidence of two super-massive black holes. At the center of galaxies near the Milky Way, they’re still millions of light-years away, but in relative terms, they’re our next-door neighbors.

3. Long-Term Marijuana Use Changes Your Brain

Marijuana is safe, as far as drugs go, but that doesn’t mean it’s totally free of long-term consequences. In a mouse study, neuroscientists found that long-term marijuana use can lead to abnormally high dopamine levels. This suggests that marijuana could be messing with your brain chemistry more than you thought.

2. Scientists Figured Out That Tattoo Ink Doesn’t Stay Put

That’s right, even though the whole idea of a tattoo is that the ink goes into your skin and never comes out, researchers have found that ink pigment nanoparticles migrate and accumulate in people’s lymph nodes. It makes sense since your lymphatic system gets rid of bad stuff and tattoo ink is essentially a foreign invader.

New blood test could help treat snake bites .


Working out whether a snake has delivered venom with its bite may one day be determined by a simple blood test, new Australian research suggests.

The discovery could dramatically improve snakebite treatment in tropical rural areas, particularly in the developing world, where snakebite is a major health issue.

https://i2.wp.com/www.abc.net.au/reslib/201406/r1285488_17443198.jpg

The work, previously published in Nature Scientific Reports, was presented this week at the Australian Society for Medical Research Annual Scientific Meeting in Sydney.

Senior author Dr Geoffrey Isbister, at the University of Newcastle‘s School of Medicine and Public Health, says the delivery of snakebite antivenom is often delayed until symptoms appear. This can sometimes be too late.

“The important thing is to be able to give the right patients antivenom early,” says Isbister. “We need to identify in the first few hours if we’ve got envenomation.”

“At the moment that is based on whether the patient feels a bit sick; but you also feel like that when you’ve just been confronted by a snake.”

Isbister says once signs of paralysis and muscle damage begin to appear, it cannot be reversed by antivenom.

“Everyone thinks [antivenom] is this magic thing, but it doesn’t reverse most things that have happened,” he says.

“You’ve got to get the antivenom into the circulation early to bind to the snake toxins before they get to the muscles, before they get to the nerves and do the damage.”

The scale of the snakebite problem is large with the World Health Organisation recognising it about four years ago as a tropical disease.

Isbister says there are one to two million cases of snake envenomation, with a potential fatality rate of 100,000 deaths worldwide.

Snakebite treatment is hampered by the availability of antivenom; high reaction rates to antivenom; and difficulties in diagnosing envenomation to allow early antivenom treatment.

Isbister says the development of a cheap diagnostic test for envenomation that can be done at the bedside is critical in addressing these issues.

Cheap detection tool

For this latest study his team, including Dr Margaret O’Leary at the University of Newcastle and Dr Kalana Maduwage from University of Peradeniya, Sri Lanka, focused on a common enzyme in snake venoms – phospholipase A2 (PLA2).

Using samples from confirmed snakebite patients in Sri Lanka and Australia they checked to see if PLA2 could be detected in the blood.

Pre-antivenom samples were collected from venomous bites from samples collected from Russell’s viper, hump-nosed pit viper, Indian cobra, Indian krait and five red-bellied black snake were included in the study. These were compared with PLA2 levels in a group of un-envenomated patients.

Isbister says the levels of PLA2 were elevated in all those who had been bitten and injected with venom.

He says confirmation of envenomation means only patients who require antivenom will receive it.

“Even in a health clinic in Africa if you have antivenom then this test would help guide whether to give it rather than travelling eight hours to a hospital where it would be too late,” he says.

Bringing it to the bedside

This can also have major financial implications even in developed countries such as Australia where antivenom is available at more than 90 per cent of hospitals, Isbister adds.

He says while thousands of cases of “snakebites” would appear at hospitals, only about five to 10 per cent would have envenomation.

“What comes into hospital is a suspected snakebite,” he says adding this can range from being “attacked” by a stick, a bite by a non-venomous snake, to an attack from a venomous snake that didn’t cause any effects.

Isbister warns against too much excitement as the analysis for this study involved expensive laboratory testing.

However, he says the “proof of concept” findings make it now feasible to begin research on development of a cheap testing kit.

“The actual test itself is not too complicated,” he says, “it’s working out a way you can do that simply at the bedside.”

Grossly warped ‘nanographene’.


Chemists at Boston College and Nagoya University in Japan have synthesized the first example of a new form of carbon, the team reports in the most recent online edition of the journal Nature Chemistry.

nanographene

The new material consists of multiple identical pieces of grossly warped graphene, each containing exactly 80 carbon atoms joined together in a network of 26 rings, with 30 hydrogen atoms decorating the rim. Because they measure slightly more than a nanometer across, these individual molecules are referred to generically as “nanocarbons,” or more specifically in this case as “grossly warped nanographenes.”

Until recently, scientists had identified only two forms of pure carbon: diamond and graphite. Then in 1985, chemists were stunned by the discovery that carbon atoms could also join together to form hollow balls, known as fullerenes. Since then, scientists have also learned how to make long, ultra-thin, hollow tubes of carbon atoms, known as carbon nanotubes, and large flat single sheets of carbon atoms, known as graphene. The discovery of fullerenes was awarded the Nobel Prize in Chemistry in 1996, and the preparation of graphene was awarded the Nobel Prize in Physics in 2010.

Graphene sheets prefer planar, 2-dimensional geometries as a consequence of the hexagonal, chicken wire-like, arrangements of trigonal carbon atoms comprising their two-dimensional networks. The new form of carbon just reported in Nature Chemistry, however, is wildly distorted from planarity as a consequence of the presence of five 7-membered rings and one 5-membered ring embedded in the hexagonal lattice of carbon atoms.

Odd-membered-ring defects such as these not only distort the sheets of atoms away from planarity, they also alter the physical, optical, and electronic properties of the material, according to one of the principle authors, Lawrence T. Scott, the Jim and Louise Vanderslice and Family Professor of Chemistry at Boston College.

“Our new grossly warped nanographene is dramatically more soluble than a planar nanographene of comparable size,” said Scott, “and the two differ significantly in color, as well. Electrochemical measurements revealed that the planar and the warped nanographenes are equally easily oxidized, but the warped nanographene is more difficult to reduce.”

Graphene has been highly touted as a revolutionary material for nanoscale electronics. By introducing multiple odd-membered ring defects into the graphene lattice, Scott and his collaborators have experimentally demonstrated that the electronic properties of graphene can be modified in a predictable manner through precisely controlled chemical synthesis.

Source: http://machineslikeus.com

 

Scientists Capture First Images of Molecules Before and After Reaction.


Every chemist’s dream — to snap an atomic-scale picture of a chemical before and after it reacts — has now come true, thanks to a new technique developed by chemists and physicists at the University of California, Berkeley.

Using a state-of-the-art atomic force microscope, the scientists have taken the first atom-by-atom pictures, including images of the chemical bonds between atoms, clearly depicting how a molecule’s structure changed during a reaction. Until now, scientists have only been able to infer this type of information from spectroscopic analysis.

“Even though I use these molecules on a day to day basis, actually being able to see these pictures blew me away. Wow!” said lead researcher Felix Fischer, UC Berkeley assistant professor of chemistry. “This was what my teachers used to say that you would never be able to actually see, and now we have it here.”

The ability to image molecular reactions in this way will help not only chemistry students as they study chemical structures and reactions, but will also show chemists for the first time the products of their reactions and help them fine-tune the reactions to get the products they want. Fischer, along with collaborator Michael Crommie, a UC Berkeley professor of physics, captured these images with the goal of building new graphene nanostructures, a hot area of research today for materials scientists because of their potential application in next-generation computers.

“However, the implications go far beyond just graphene,” Fischer said. “This technique will find application in the study of heterogeneous catalysis, for example,” which is used widely in the oil and chemical industries. Heterogeneous catalysis involves the use of metal catalysts like platinum to speed reactions, as in the catalytic converter of a car.

“To understand the chemistry that is actually happening on a catalytic surface, we need a tool that is very selective and tells us which bonds have actually formed and which ones have been broken,” he added. “This technique is unique out there right now for the accuracy with which it gives you structural information. I think it’s groundbreaking.”

“The atomic force microscope gives us new information about the chemical bond, which is incredibly useful for understanding how different molecular structures connect up and how you can convert from one shape into another shape,” said Crommie. “This should help us to create new engineered nanostructures, such as bonded networks of atoms that have a particular shape and structure for use in electronic devices. This points the way forward.”

Fischer and Crommie, along with other colleagues at UC Berkeley, in Spain and at the Lawrence Berkeley National Laboratory (LBNL), published their findings online May 30 in the journal Science Express.

From shadow to snapshot

Traditionally, Fischer and other chemists conduct detailed analyses to determine the products of a chemical reaction, and even then, the actual three-dimensional arrangement of atoms in these products can be ambiguous.

“In chemistry you throw stuff into a flask and something else comes out, but you typically only get very indirect information about what you have,” Fischer said. “You have to deduce that by taking nuclear magnetic resonance, infrared or ultraviolet spectra. It is more like a puzzle, putting all the information together and then nailing down what the structure likely is. But it is just a shadow. Here we actually have a technique at hand where we can look at it and say this is exactly the molecule. It’s like taking a snapshot of it.”

Fischer is developing new techniques for making graphene nanostructures that display unusual quantum properties that could make them useful in nano-scale electronic devices. The carbon atoms are in a hexagonal arrangement like chicken wire. Rather than cutting up a sheet of pure carbon — graphene — he hopes to place a bunch of smaller molecules onto a surface and induce them to zip together into desired architectures. The problem, he said, is how to determine what has actually been made.

That’s when he approached Crommie, who uses atomic force microscopes to probe the surfaces of materials with atomic resolution and even move atoms around individually on a surface. Working together, they devised a way to chill the reaction surface and molecules to the temperature of liquid helium — about 4 Kelvin, or 270 degrees Celsius below zero — which stops the molecules from jiggling around. They then used a scanning tunneling microscope to locate all the molecules on the surface, and zeroed in on several to probe more finely with the atomic force microscope. To enhance the spatial resolution of their microscope they put a single carbon monoxide molecule on the tip, a technique called non-contact AFM first used by Gerhard Meyer and collaborators at IBM Zurich to image molecules several years ago.

After imaging the molecule — a “cyclic” structure with several hexagonal rings of carbon that Fischer created especially for this experiment — Fischer, Crommie and their colleagues heated the surface until the molecule reacted, and then again chilled the surface to 4 Kelvin and imaged the reaction products.

“By doing this on a surface, you limit the reactivity but you have the advantage that you can actually look at a single molecule, give that molecule a name or number, and later look at what it turns into in the products,” he said.

“Ultimately, we are trying to develop new surface chemistry that allows us to build higher ordered architectures on surfaces, and these might lead into applications such as building electronic devices, data storage devices or logic gates out of carbon materials.”

The research is coauthored by Dimas G. de Oteyza, Yen-Chia Chen, Sebastian Wickenburg, Alexander Riss, Zahra Pedramrazi and Hsin-Zon Tsai of UC Berkeley’s Department of Physics; Patrick Gorman and Grisha Etkin of the Department of Chemistry; and Duncan J. Mowbray and Angel Rubio from research centers in San Sebastián, Spain. Crommie, Fischer, Chen and Wickenburg also have appointments at Lawrence Berkeley National Laboratory.

The work is sponsored by the Office of Naval Research, the Department of Energy and the National Science Foundation.

Source: physics.org