October
Chemistry World Podcast - October 2008
00:10 -- Introduction
02:09 -- A failed anxiety drug could provide a novel treatment for cancer
04:29 -- A biosensor made from proteins could speed drug development
06:43 -- Fred Vom Saal from the endocrine disrupters group at the University of Missouri-Columbia explains the clinical concern over a chemical commonly found in plastics - bisphenol A
12:58 -- How to break the bonds of global warming
15:55 -- How plants manipulate their pollinators with chemicals
18:14 -- Medicinal chemist Robert Fecik from the University of Minnesota takes us through the latest research in the quest to find new superbug-beating antibiotics
24:44 -- Lab on a chip could improve IVF by identifying healthy embryos before implantation
27:15 -- How to play pinball with atoms
29:57 -- What seasonal fruit is associated with the atom? And do you know the answer to our Nobel-themed chemistry conundrum?
(Promo)
Brought to you by the Royal Society of Chemistry, this is the Chemistry World Podcast.
(End Promo)
(00:10 -- Introduction)
Interviewer - Chris Smith
Hello! Welcome to October edition of Chemistry World Podcast with Victoria Gill, Richard Van Noorden, and Ananyo Bhattacharya. I'm Chris Smith. Coming up, how a drug that was originally intended to tackle anxiety has now found a new lease of life, combating cancer.
Interviewee - Victoria Gill
What this does give the researchers is, sort of, a new paradigm for cancer drug design, so they have a small molecule that they know a lot about, they've, sort of, toxicity tested it and they've got it to early stage clinical trials, so they could use that to design new cancer drugs that interact specifically with this messenger.
Interviewer - Chris Smith
You can hear how it works shortly, also on the way bisphenol A, it's in tin cans and plastic bottles and that means it's probably also in us, but is it dangerous?
Interviewee - Fredrick S. Vom Saal
What we know from animal research is if you take young animals and you feed them that amount of bisphenol A, you have brain damage, reproductive damage, immune damage, liver damage; you damage virtually every system in the body.
Interviewer - Chris Smith
Well that's Fred Vom Saal who'll be explaining why should not boil your baby bottles later in the program. We also get the answer to another organic nuisance.
Interviewee - Richard Van Noorden
This is some very nifty chemistry. A catalyst and a reagent combination together used to breakdown the famously strong very inert carbon-fluorine bond at room temperature. Fluorocarbons are persistent organic pollutants. They do build up in penguins, if they are gases they do buildup in the atmosphere and they are potent greenhouse gases.
Interviewer - Chris Smith
Plus if you cast your mind back to last month's autumnal chemical conundrum...
Interviewee - Richard Van Noorden
If you lived a 100 years ago, which seasonal British fruit would you associate with the atom. So if you've sent in a fruity suggestion then you could be one of this month's winners. The answer is on the way.
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02:09 -- A failed anxiety drug could provide a novel treatment for cancer)
Interviewer - Chris Smith
First this week, scientists have found Victoria, that a drug originally intended to knock anxiety on the head actually does a much better job of blocking the overgrowth of cancer cells and in an entirely novel way.
Interviewee - Victoria Gill
Yeah exactly, a failed drug it would seem at this clinical level that they thought had effects on anxiety and now it turns out that it could be used to treat cancer in a brand new way that hasn't been seen before. So this is work that comes out of the University of Helsinki, Paavo Kinnunen and his group and the drug is already being tested at sort of, very early clinical stages and it's called siramesine. It acts at the cellular level on a specific receptor on the cell membrane and that was what they were hoping and would have the effect against anxiety. It's a particular receptor on neurons. But at the clinical level, it just didn't seem to work.
Interviewer - Chris Smith
So how did they then decide to apply it to cancer?
Interviewee - Victoria Gill
As you know with testing a drug from very early stages of discovery right through to approval, it costs lot of money, so if you find that your drug fails at a very early stage, you might want to look into another effect that it might have. So looking at it in cell cultures they found that it has an anticancer effect. It seems to prevent cancer cells from proliferating or, sort of, reproducing themselves.
Interviewer - Chris Smith
Do they know how?
Interviewee - Victoria Gill
Yes they do and it's a brand new way that hasn't been seen before. It interacts with a second messenger molecule, a phospholipid on the cell membrane and this phospholipid is a second messenger to stimulate a biochemical pathway that causes the tumour cells to proliferate and it binds and interacts with this phospholipid which is called phosphatidic acid and prevents this second messenger from being used, so the cancer cells can't reproduce.
Interviewer - Chris Smith
I can see that they are really useful, but one worry is, if all cells use this mechanism, will it not have terrible side effects.
Interviewee - Victoria Gill
Potentially and that's always a problem with quite harsh, sort of, cytotoxic, cell killing cancer drugs, but what this does gives the researchers is, sort of, a new paradigm for cancer drug design, so they have a small molecule that they know a lot about. They've, sort of, toxicity tested it and they've got it to early stage clinical trials, so they could use that to design new cancer drugs that interact specifically with this messenger and they can, sort of, design out the side effects.
Interviewer - Chris Smith
Thanks Vic. So that's very exciting. Let's hope that that makes its way into the clinic soon.
(04:29 -- A biosensor made from proteins could speed drug development)
Interviewer - Chris Smith
And talking of people discovering new drugs Ananyo this is very exciting, it looks like there's a new way for people to determine whether or not the thing that they think is targeting certain structures on cells that's working or not.
Interviewee - Ananyo Bhattacharya
Yeah that's right Chris, it's an invention of researchers in France that come up with a biosensor that can tell you if your drug is binding to the right, sort of, target on a cell. That could be tremendously useful for the pharmaceutical industry because it would allow them to screen large numbers of drugs very directly and quickly. And what they did to come up with this is that they got a protein called G-protein coupled receptor. It's a very common target for many many drugs, I think about 30% of all drugs bind to this receptor. And they coupled that to another protein called an ion channel and this ion channel regulates the flow of ions in and out of cells and what they did with a clever piece of genetics engineering itself, they linked the two so that when a drug bounds the G-protein coupled receptor it target on the ion channel opened it up and the ions flowed and you got an electric current which they could then measure.
Interviewer - Chris Smith
So you can work out exactly how active the drug is at the cell surfaces. So you've effectively got an objective reader out here.
Interviewee - Ananyo Bhattacharya
Yeah, it's all very direct and very very sensitive. I mean at the moment what the pharmaceutical industry does is they have various indirect methods like the use radioactive tags or fluorescent tags on their compound and they see whether it's binding roughly to the protein that they are interested in; or what they do is the monitor a cell and see if it's producing the sort of biochemical changes in the cell that they would expect, but this sensor is, you know, it could offer a much more direct way of saying if that drugs is working.
Interviewer - Chris Smith
Is this something which could be used tomorrow or is this really just proof of principle and it's going to be ages before we can really see drugs being produced because of this.
Interviewee - Ananyo Bhattacharya
I suspect it's more of the latter. I think there's a way to go, for example, one of the questions raised by a scientists we talked to was that but what happens if your drug is triggering the ion channel and how do you know you going to have to try and differentiate between that and the G-protein coupled receptor.
Interviewer - Chris Smith
So good news for the pharmaceutical sector. Thank you Ananyo.
(06:43 -- Fred Vom Saal from the endocrine disrupters group at the University of Missouri-Columbia explains the clinical concern over a chemical commonly found in plastics - bisphenol A)
Interviewer - Chris Smith
Something that all new parents take very seriously is food hygiene. Most people obsessively sterilize their baby's bottles, often by nuking them in the microwave for 10 minutes or soaking them in boiling water; any one of them. But now some scientists are saying that the baby might be better of taking its chances with the bacteria rather than the Bisphenol A that is leaking out of the plastic. Here's Fred Vom Saal.
Interviewee - Fredrick S. Vom Saal
Bisphenol A is a chemical that's used to make hard, clear, reusable plastic products that are used as food containers, sport water bottles, baby bottles, microwavable safe containers for food, also to line food and beverage cans and it is used in many many other applications. There are 7 billion pounds of this manufactured and put into products a year, but our main concern is it's used as a food contact item, where we think the greatest human exposure is coming from and based on data from Europe and Asia and the United States virtually everyone has detectable levels of Bisphenol A in his or her body and that of course is a very serious concern.
Interviewer - Chris Smith
Why is it so ubiquitously used in the ways you have just described?
Interviewee - Fredrick S. Vom Saal
Actually it does not need to be. All of the products that are made with Bisphenol A in countries like Japan particularly all of them have been replaced, particularly the food contact items. It's not used to line cans anymore. This is a chemical that became used extensively at a time that people did not understand that it is structurally very similar to the oestrogen drug diethylstilbestrol and has the same activity of the natural oestrogen produced in a person's body. So we have referred to this as an endocrine disrupting chemical and it acts like a sex hormone when it breaks out of the polymer that forms this hard, clear, odourless, tasteless material. The problem is that it is quite unstable when heated and people are told that they can take baby bottles for instance and stick them in boiling water. Well there are plenty of data out there now that when you do that you break apart the Bisphenol A molecules out of this polycarbonate plastic and the baby is then drinking Bisphenol A along with its baby formula.
Interviewer - Chris Smith
On a normal day-to-day basis, what sort of dose are we getting?
Interviewee - Fredrick S. Vom Saal
Well there is consensus for baby's drinking baby formula out of baby bottles. They are getting somewhere between 2 and 14 mcg/kg/day. What we know from animal research is if you take young baby animals and you feed them that amount of Bisphenol A you have brain damage, reproductive damage, immune damage, liver damage; you damage virtually every system in the body and among other things those animals become obese; they go into early puberty, so you have metabolic derangement as well. So this is a chemical that particularly in early life causes a tremendous an amount of harm.
Interviewer - Chris Smith
And if you look at the health risks and published clinical data on people who have been exposed, is the clinical data bearing out what's you're saying?
Interviewee - Fredrick S. Vom Saal
So last week in the Journal of the American Medial Association, David Melzer's group in England published a study based on the United States National Health Survey showing that the higher your levels of Bisphenol A the more likely you were to show elevated insulin levels, elevated glucose levels, insulin resistance, liver damage and cardiovascular disease including the higher probability of dying of a heart attack.
Interviewer - Chris Smith
What about the alternatives, because if you're saying that at least people have an alternative and Bisphenol A is not used, what will they use instead and what's the evidence that that's any safer?
Interviewee - Fredrick S. Vom Saal
There are other kinds of polymers that are made from chemicals like polyethersulphone, which is sulphone molecules linked together that are highly resistant to breaking down under heat or acidic or basic conditions such as heating up in a can of tomato sauce where you get this massive amounts of Bisphenol A being found, so if you have a stable material that is not going to leech out into the food, it is going to be inherently safer even though it may be as a molecule potentially as dangerous as Bisphenol A if you are not exposed to it, it doesn't pose a danger.
Interviewer - Chris Smith
Well that's certainly food for thought. That was Fred Vom Saal from the University of Missouri talking about the effects of Bisphenol A that's leaking out of the things that we use to store food in and if you like to follow up on the article that Fred mentioned, it is in the 17th of September 2008 edition of the Journal of the American Medical Association.
(Music)
Interviewer - Chris Smith
This is the Chemistry World podcast with me Chris Smith still to come how plants trick pollinators so they don't just stay there welcome, two new ways to battle drug-resistant bacteria and IVF on a chip.
(12:58 -- How to break the bonds of global warming)
Interviewer - Chris Smith
First though Richard scientists have found a way to breakdown persistent organic pollutants including the notorious carbon-fluorine bond.
Interviewee - Richard Van Noorden
Exactly this is some very nifty chemistry. A catalyst and a reagent combination together used to breakdown the famously strong, very inert carbon-fluorine bond at room temperature. It's from Oleg Ozerov's group at Brandeis University in Massachusetts and fluorocarbons are persistent organic pollutants. They do build up in penguins; if they are gases they do build up in the atmosphere and they are potent greenhouse gases.
Interviewer - Chris Smith
Why do they build up?
Interviewee - Richard Van Noorden
Well it's very very hard to breakdown that carbon fluorine bond, very inert. So they just hang around for thousands of years and there's no natural process by which they could either be broken up into smaller pieces.
Interviewer - Chris Smith
And what does this team done to try and solve the problem?
Interviewee - Richard Van Noorden
This team had earlier shown that if you have got a very strong Lewis acid, a cation that pulled electrons away from the carbon-fluorine bond, you could get that bond to break but unfortunately that was very short lived and when it break a few and then that was it.
Interviewer - Chris Smith
It was also not very practical on a global scale given these things were accumulating in the atmosphere and in the sea to do that is it?
Interviewee - Richard Van Noorden
Well the idea here would actually be to try and store what you've got and break it down in a reactor. They haven't yet got to the stage of deciding what to do about the things that have already built up. But for this chemistry they had already shown that an acid can break down the carbon-fluorine bond; it didn't hand around long. Here they have got another strong solo cation, it's actually a silylium surrounded by three other groups which is a cation and there is a balancing counter ion, a carborane which doesn't really get in the way much, so the cation is free to pull away the fluorine from the carbon-fluorine bond not easily with the positively charged carbon and they have got another reagent coming in triethylsilane which is a positively charged silicon but you have got hydrogen on the end making it a molecule and that hydrogen is taken by what was your carbon-fluorine bond you end up with the hydrocarbon, a carbon hydrogen bond that's much right for the environment. Now your catalysts will then turn over, your reagents being used up and you will end up with fluorine sort of being bonded with carbon being bonded with the silicon and the researchers say that that has a less of an impact on the atmosphere.
Interviewer - Chris Smith
So what's the resulting product?
Interviewee - Richard Van Noorden
Silicon surrounded by hydrocarbons with a fluorine atom attached to it. Previously you had fluorine attached to carbon
Interviewer - Chris Smith
And they say this is better for the environment; it's a lesser degree greenhouse gas than the carbon-fluorine bond we had there before.
Interviewee - Richard Van Noorden
Yes they do.
Interviewer - Chris Smith
What's about environmental safety to animals, to humans, that kind of thing?
Interviewee - Richard Van Noorden
Well the idea would not be to let this stuff leak out into the environment, it may indeed turn out to be toxic, but the idea there, that's clever chemistry, you can break down this bond, is what really that which excites them, now they haven't tried this is on a kilogram scale. We are just talking catalyst lab scale good turnover, but it's just extremely amazing that at room temperature you can actually break down this strong bond.
Interviewer - Chris Smith
I guess we just have to wait and see what the long term future holds for that particular bit of chemistry. Thanks Richard.
(15:55 -- How plants manipulate their pollinators with chemicals)
Interviewer - Chris Smith
Now Victoria, back on to something which is very much an issue that has been going on for thousands of years and that's pollination of plants and scientists have got to the bottom of how plants manage to sort out the weed from the chaff if you like.
Interviewee - Victoria Gill
Indeed, I mean, it seems that they use a, kind of, clever bit of chemistry to trick their pollinators. This is work that comes out of the Max Planck Institute of Chemical Ecology in Jena and Ian Baldwin and his team have discovered that plants use a very finely tuned mixture of attractants and repellent chemicals to sort of tease pollinators into pollinate them and take their nectar.
Interviewer - Chris Smith
So, on the one hand they are attracting them or giving them something nice and at the same time repelling them.
Interviewee - Victoria Gill
Yes, and then using a sort of toxic chemical to repel them to make them go away before they have taken all the nectar and so that other pollinators will have a chance to pollinate plants. That way they get to reproduce more successfully.
Interviewer - Chris Smith
Okay, so in other words if you had something that was entirely attractive, a nice juicy flower full of nectar, then greedy insects might be tempted to just spend all day on one flower.
Interviewee - Victoria Gill
Yes.
Interviewer - Chris Smith
And that would not fulfil any of the obligations of being a pollinator.
Interviewee - Victoria Gill
Exactly!
Interviewer - Chris Smith
Because they would not carry any pollen.
Interviewee - Victoria Gill
And that flower wouldn't be able to, sort of, spread its seeds and reproduce successfully as other plants.
Interviewer - Chris Smith
So what did they do to prove this was what the plants were doing?
Interviewee - Victoria Gill
So they have been studying these particular tobacco plants for a long time now and they have discovered that there are two chemicals that are the most important attractant and repellent chemicals. Benzyl acetone is their most important attractant and nicotine is the most important repellent and they used fake flowers with these particular chemicals on to show that these attracted and repelled pollinators, bees and humming birds. So using RNA interference which is a method of, sort of, silencing a particular gene that makes a chemical for example, they have silenced the genes that make benzyl acetone the attractant and the nicotine, the repellent. And so they have generated plants that produce either just repellents or just attractants or a balanced mixture of the two. And they have videoed these plants to see how much they are visited by pollinators and what they have found is that the plants have to have this very delicate balance of the two chemicals in order to be visited by as many pollinators as possible.
Interviewer - Chris Smith
Sneaky plants. You do have to wonder though whether the pollinators are actually hooked on the nicotine and that's why they keep coming back. Thank you Victoria.
(18:14 -- Medicinal chemist Robert Fecik from the University of Minnesota takes us through the latest research in the quest to find new superbug-beating antibiotics)
Interviewer - Chris Smith
And now to the question of antibiotic resistance and the race to develop new drugs to combat bacteria that are becoming increasingly more difficult to deal with. Thankfully, now scientists have got two new targets to aim at. Here's Robert Fecik.
Interviewee - Robert Fecik
Well the issue addressed by the two papers is the lack of new antibacterial drug targets. It's been widely recognized that there has been a lack of new antibiotics in the drug industry pipeline. Part of the problem has been a dearth of new drug targets that could be exploited for antibacterial drugs and so in these two papers the authors have set out to try to establish or validate a certain drug targets that could be exploited for antibacterial therapy.
Interviewer - Chris Smith
So briefly how does these two new targets that they have uncovered work, what approaches do they take, which are different to those antimicrobials that we already have to throw to patients at the moment.
Interviewee - Robert Fecik
In the first paper this was published by scientists at Prolysis. They have identified a protein called FtSZ, sometimes it is referred to as FitSZ, this is a protein that is critical for cell division in bacteria and so this is very vital for them to grow and this protein, FtSZ attracted a lot of attention because it turns out that this is the homologous in bacteria to Tubulin in mammals and Tubulin is a well known anti-cancer drug target. This is a target of drugs such as Taxol, Vinblastine, Vincristine and so the idea is that if this Tubulin protein is effective to stop cancerous cells growing then the homologous protein in bacteria should also be an effective antibiotic treatment to stop bacteria from growing.
Interviewer - Chris Smith
How do the bacteria use the protein?
Interviewee - Robert Fecik
This FtSZ protein forms what is called the Z-rings and the protein polymerizes to form a ring on the inside of the bacterial cell wall as it is undergoing cell division and the presence of this ring then helps to recruit other proteins to this ring site that enables the process of cell division to occur.
Interviewer - Chris Smith
All right so this is how bacteria quite literally split in two when they undergo binary fission and one bacterium becomes two.
Interviewee - Robert Fecik
Correct.
Interviewer - Chris Smith
So how does this agent actually affect that protein and therefore stop the bacteria dividing?
Interviewee - Robert Fecik
So the compound reported in this study has a code named PC190723. This compound actually prevents the FtSZ protein from polymerizing, so you can think of it as an agent that blocks the formation of this Z-ring. This essentially shuts down the key event that needs to take place for bacteria to divide and grow.
Interviewer - Chris Smith
So we know that this new agent works and it can stop the bacteria from dividing presumably or is this just has been done in vitro.
Interviewee - Robert Fecik
In the current study, the authors have taken this one stop beyond in vitro work that others have demonstrated and have now taken this into an in vivo mouse model of bacterial infection and for instance they have found that upon single injection over a 7-day time period that this compound that inhibits FtSZ polymerization cures mice of a lethal infection.
Interviewer - Chris Smith
And is this target found in all kinds of bacteria or are there certain subtypes of bacteria and therefore it's not going to be panacea for everything, and it will only cure a some certain infection for certain types of bacteria.
Interviewee - Robert Fecik
So FtSZ is almost entirely conserved amongst all bacteria and so presumably this could be a very broad-spectrum type of antibiotic, however, one interesting thing that has been found by a number of groups is that compounds that inhibit FtSZ polymerization are generally more effective against gram-positive organisms and so the most clinically significant of these are multi-drug resistant Staph aureus or MRSA infections and so this tends to lead to some hope that perhaps in agents such as this could be a targeted type of antibacterial infection that could be reserved for multi-drug resistant infections, particularly gram-positive ones.
Interviewer - Chris Smith
Unless Fecik, we certainly need some. So that's one of the publications. There was a second paper, this was the group in Japan and they have been looking at a slightly different target.
Interviewee - Robert Fecik
Yes and so the group in Japan Tohru Dairi, they have been looking at a protein called menaquinone and this is a protein that plays a critical role in bacterial respiration and so bacteria need proper functioning of this to survive. However, they found that there are certain strains of H. pylori or this is the bacteria which commonly causes stomach ulcers that they use an alternate pathway and so they actually produce a different type of protein critical for bacterial respiration and so this suggests again getting back to the theme of selective antibacterial agents or targeted antibacterial agents that interfering with this pathway that has only so far been found in H. pylori that this could be a selective antibiotic agent useful for the treatment of stomach ulcers.
Interviewer - Chris Smith
So another promising target, but how long do you think it would take before this one and the previous agent that we talked about will actually find their way into patients?
Interviewee - Robert Fecik
It will likely be a number of years before any agents from these studies could be translated into clinical useful therapies. Establishing in vivo animal efficacy data is one of the essential early steps and so there is much work to be done here for instance we know nothing up long term toxicity of these agents, potential side effects and other types of infections that these compounds could be potentially useful in and so it would likely be 3 to 5 years potentially till a new agent at this stage could enter human clinical trials.
Interviewer - Chris Smith
That's Robert Fecik from the University of Minnesota.
(Music)
Interviewer - Chris Smith
You're listening to the Chemistry World podcast and coming up shortly how scientists have built an atomic scale pinball machine and the answer to this month's chemical conundrum.
(24:44 -- Lab on a chip could improve IVF by identifying healthy embryos before implantation)
Interviewer - Chris Smith
But first good news for IVF, because scientists have developed a technique that might help to boost the success rate of the procedure by helping them to identify the healthiest embryos, Ananyo what's this about?
Interviewee - Ananyo Bhattacharya
Yes Chris. So these scientists at MIT have come up with a poster stamp size device which they say could help to determine whether an IVF embryo is healthy prior to implantation.
Interviewer - Chris Smith
How does it work?
Interviewee - Ananyo Bhattacharya
Well, what they have got is a microfluidic chip and it measures the nutrients that an embryo is taking in and the moment it measures 3 key nutrients, a glucose pyruvate and lactate, now when these nutrients gets taken in they are catalyzed by an enzyme called nitrite reductase enzyme or NAD(P)H and this enzyme fluoresces in its reduced form, so what they have done is that they have found a way of picking up on that light and they used that to tell whether the embryo is healthy or not.
Interviewer - Chris Smith
So in other words they are using this indirect measure of health, because by measuring the metabolic profile of the embryo, in other words the ability to break down those three substances you can tell whether or not it's within the normal range if by chemical parameters.
Interviewee - Ananyo Bhattacharya
That's exactly what they are trying to do, yeah, although it's all a bit controversial at the moment. I mean they claim, at the moment, they have only done that with mouse cells, mouse embryos, so they haven't yet applied it to humans. They seemed to think that's not too difficult, but then researchers we contacted said that the three metabolites they have chosen, the three nutrients, haven't really been linked to the viability of the embryo later. They need to demonstrate that the nutrients that they have shown actually correlate well with whether an embryo would grow or not.
Interviewer - Chris Smith
And also the different species, because this is a proof of principle presumably mice and small rodent work, is it likely that a human embryo much bigger could be an entirely different ball park.
Interviewee - Ananyo Bhattacharya
Yeah, yes it might be, I mean, as I say the researchers are confident that they can use basically the same technology with human embryos, but it sounds like they are going to have to look at a completely different spectrum of nutrients and metabolites to get this right.
Interviewer - Chris Smith
Well there's still an important step forward, because at the moment it's taking guess work and at least putting some numbers on it, because that's what it is. The present technique is nothing more than really guess work under microscope, isn't that how you guess?
Interviewee - Ananyo Bhattacharya
Yeah, at the moment about 25% of IVF embryos are successfully implanted, so any device that can help get that number up is going to be very welcome.
Interviewer - Chris Smith
Especially with the price tag being what it is for IVF, Thanks Ananyo.
(27:15 -- How to play pinball with atoms)
Interviewer - Chris Smith
Now, Richard lets get even smaller now and down at the level of individual atoms. This sounds extraordinary, how you can turn platinum atoms into the equivalent of a pinball game.
Interviewee - Richard Van Noorden
Yep, that's right, remember the pinball flippers and the old games, you don't see them around anymore, but Harold Zandvliet and colleagues at the University of Twente have discovered a little atomic version of these pinball flippers. What they did was they had platinum atoms deposited on to a germanium surface, trying to make nanowires and you get all these atoms, they actually sort of make diamonds. They sort of collect together in pairs. When they were inspecting these atoms with a scanning tunnelling microscope a tip comes down, an electron stream from the tip on to the surface and they actually found that some of these pairs were flipping pivoting up and down like flippers, you could actually get two next to each other flipping in synchrony or not in synchrony, incredible that you can show that something on the atomic scale you can have what is effectively a switch from outside causing this flipper like, machine like motion.
Interviewer - Chris Smith
Bizarre, but why does it do it?
Interviewee - Richard Van Noorden
Well, they have no idea why it does it, and they have no idea how to recreate getting these pairs on the surface but of course they have their suspicions and they have done some experiments to try and found out why. From what they think is that in the germanium subsurface underneath these pairs of platinum atoms, you do have missing atoms sometimes. And they reckon the platinum atom above this vacancy is allowed to swing free and the other platinum atom is fixed and acts as a pivot, so this could just be a chanced thing. They also don't know how the current coming in causes that swinging to happen. It's very exciting. It's very intriguing but they really have no idea beyond that at this stage. But it is one of those discoveries that's just so intriguing that you could get atomic scale machinery.
Interviewer - Chris Smith
Does the frequency of flips tell you anything about the structure of the surface or the chemistry what's going on?
Interviewee - Richard Van Noorden
They know that increasing the strength of the current increases the flipping frequency and I think that is as far as they've got.
Interviewer - Chris Smith
And to finish of Richard, how do they see this being used or do you think it's just one of those wonderful terrific discoveries that looks great but actually isn't terrifically useful.
Interviewee - Richard Van Noorden
Well, Zandvliet says, currently, we don't see any applications for it, we stumbled on it by luck, we immediately decided to work on it because it is an interesting feature, but lets get this in perspective, the awesome idea of nanotechnology is to be able to make machines on the atomic scale and this is a machine on the atomic scale and of course they can't control it, they can't get it where they want to, but it just shows the kind of thing that might be possible in 20 or 30 years or let me understand more about what's going on the atomic scale on the surface.
Interviewer - Chris Smith
Thanks Richard. Atomic pinball wizard, Richard Van Noorden.
(29:57 -- What seasonal fruit is associated with the atom? And do you know the answer to our Nobel-themed chemistry conundrum?)
Interviewer - Chris Smith
Now Richard talking of atoms in last month's chemical conundrum we wanted to know what seasonal fruit would have been associated with an atom about a century ago. So, what's the answer?
Interviewee - Richard Van Noorden
Well the answer was as many of you got a plum referring to J.J. Thompson's model of the atom as a plum pudding with the plums supposed to be surrounded by a morass of negative charge and all that was changed by Rutherford when he famously bounced particles of the positive nucleus in the centre of the atoms in gold leaf, leading to the model that we know today.
Interviewer - Chris Smith
Thank you Richard and well done to Keith Moore, Holy Atton, Tom Cronin and Victoria Blair who were the first. This month you have won yourselves a Chemistry World goodie bag, very sought after and if you like to win one next month, Victoria what do you want to know from people.
Interviewee - Victoria Gill
Well, sticking with the Nobel theme since its October, it is 50 years since this scientist, the only scientist ever to have won two Chemistry Nobel prizes, won his first Nobel, what is his name and which protein would you associate him with? So could you please send your answers to chemistryworld at rsc dot org and please don't forget to include your name and address so that we can post to you your goody bag.
Interviewer - Chris Smith
Oh, sneaky question, thank you Victoria and you can also use that address to send us your thoughts and feedback about this or one of our previous Chemistry World podcasts. Don't forget that we also produce a weekly podcast called Chemistry in its Element where we take a look at the sinister side of the periodic table. You can find Chemistry in its Element on I-tunes or via or our website that's chemistryworld dot org forward slash elements. Chemistry World was brought to you this month by Victoria Gill, Richard Van Noorden, and Ananyo Bhattacharya. The production was by Meera Senthilingam from the thenakedscientists dot com and I'm Chris Smith. Until next time, Good bye!
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