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hello and welcome to technically speaking where scientists and engineers come together to chat about a common interest share knowledge and satisfy some curiosity I'm Antonia and I'm joined by Laura and Emma to talk about nanoparticles and what they're used for so Laura you brought this topic up how come when I was still in Academia quite a few years ago now and I was doing a lot of work on radiation science and Material Science as well lots of scientists seems to be working on
nanomaterials for different applications like radiation sensitization and electronics and it just it seemed kind of Novel and new it actually turns out it's not yeah it's not the newest technology I thought it was but it's new to me which is exciting yeah yeah and uh sensiti sensitization we'll have to discuss that later and I actually did an internship where I was working with nanop particles I was helping make them with better quality I'm not sure I actually know how
how they actually work I know what I was doing in that small uh context I'm hoping uh Emma with your background in physics you might be able to uh explain how they work yes I I think I'm completely the opposite to you as well whereas I know how they work but in terms of real life applications and why is this important I do not really know so yeah I hopefully can definitely share some stuff on the quantum side of things which is very kind of scary word sometimes but in fact it's very much my
bread and butter GL someone is comfortable swimming in that uncertainty Laura when you were learning about nanop particles in your field what were the key things about it well from what I can tell the reason Nano particles are so interesting is because they're small enough that they have different properties than standard siiz particles so a nanop particle is defined as something that's less than 100 nanometers in diameter generally which is about the same size
as a virus particle and Emma mentioned something about Quantum effects and essentially it means they're so small that the electrons kind of act differently they're not averaging out all their behavior and they end up occupying sort of these discrete energy levels that you hear about when you looking at individual atoms that's what I understand about it anyway but I'm hoping that Emma can provide a slightly more thorough explanation yes hopefully one thing to understand I think about when things
behave as Quantum particles versus classical particles where classically particles might follow Newton's Laws particles follow Quantum regimes when they are one of two things and or both I think actually uh so one of them is really really cold temperatures where the behavior of the particle seems to change from regular temperatures um like literally around 0 Kelvin or when you're really really small scales and really really small sizes they start to exhibit these quantum effects the quantum size
effect means that when just I feel like I'm repeating exactly what you said Laura you just explained it amazingly nice but when you have these small scales the individual atom becomes in terms of size fraction of the scale you're looking at it becomes almost all of the scale you're looking at if that makes sense whereas if you're looking at larger scales the individual atoms are so small compared to that you look at this kind of larger Behavior whereas on the smaller scale you can kind of
it doesn't necessarily work like this but imagine if you're looking at the right scale you can actually see the atoms and see how they behave more exactly and how they behave is quantum mechanically which basically just means strangely and weely so almost like if we imagined these particles were individuals instead or the atoms are individuals or you're looking at an entire crowd like people could be wiggling around weirdly but generally they're all moving towards in One
Direction I would say that's a really good analogy or even just like a a loud conversation in a room when you're at these kind of quantum effects you can start to hear specific things that people are saying and you get to resolve individual behavior of the individual atoms rather than this kind of mass property so Laura you mentioned that nanop particles tend to be below 100 nanometers and Emma you've said we're looking at sort of more onto the scale of individual atoms instead of a a
collective mass of a material how many atoms are we talking about from my maths which isn't hugely accurate it was a rough back of the envelope calculations we like to say it's about 200 to 1,000 atoms obviously that depends on the size of the nanop particle and what it's made of but that is quite a small number if you look at things that I was modeling which were some fairly longish polymers there were thousands and thousands and thousands of atoms in my atomistic
modeling simulation that I was working on so these are really small I mean also to add context like a mole of a substance is 10 to 23 atoms which is lots and lots yeah and if we had like what is it a mole of say carbon dioxide it's 44 gr I can't really visualize what a gas looks like is 44 gr though I guess you're choosing that Antonia because you tend to look at carbon dioxide a lot in your job in sustainability and Energy Research oh but I don't know if that's
actually a mle now I've questioned myself I was slightly wrong it's like 43 G now wow that's so close so I've just talked a lot about physics and quantum mechanics but as I said I don't really know applications and things so where are these nanop particles like what are they used in and what are they made of even can they be made of anything the one that I've heard most applicational were nano silver and gold and they exhibited properties we didn't necessarily see in the normal size
versions it's weird I'm like thinking of the mini mini mini mini version versus the big version it's very different yeah I suppose Gold's quite a well-known one because the Nano particles are often red rather than golden in color um that's cuz they've got different Optical properties because their size and that that one of the reasons they're really famous is because they were used to color glass way back when this is a very good example of glass from Roman times
and it's it's a cup and it's green if light is passing through it as being scattered around it I should say um so if you're just looking at it under normal daylight you put a light inside of this glass vessel it suddenly turns red difference between transmission and reflectance I just Googled that that's amazing that's pretty cool yeah it's quite a good visual example of the difference between nanop particles and a normal size materi like Antonia yeah that also turns to me yeah nanop
particles whilst seemingly a new technology we've actually managed to as a society work with nanop particles I think the reason nanoparticle technology in science has become so much more active as an area of research recently is because technology developed that we could actually see them you know we had microscopes was the 1980s when some crystallites of a size range in nanometers were seemed to have different properties and they did so much research into them to figure out why kind of set
off this whole new research Paradigm I guess yeah Anton you mentioned silver as well that's T tends to be used as an antibiotic doesn't it yeah so they found that antibacterial properties with nano silver so you have nano silver plasters other types of wound dressing I wanted to find out how it works and apparently there isn't a consensus on the actual uh mechanism that is happening between the silver particles or silver atoms and the bacteria that it is basically killing
researchers have a number of suggested mechanisms which I thought was interesting that it's still quite a new field yeah I think you might have read the same research article I did it was um in the Journal of nanom Medicine I think it's published in 2020 it's about Dentistry it's applications there wasn't it yeah they had a great infographic I suppose of different possible interactions between silver and bacterium yeah I'm going to guess that the reason one of the reasons it's so
popular is because the particle size is small enough that it can penetrate the bacterium and do various things to specifically why silver and not some other nanop particle I guess it's because the exact properties that it has did that infographic tell you I don't have it in front of me to refer back to no they said mostly that again it was crossing the membrane and essentially denaturing enzymes or even the protein or DNA but why silver not sure about that sowing about the silver plus ion I
can say from a kind of protein science perspective like the proteins are held together by bonds and ions are very very important so I I can definitely imagine that any kind of shift in charges that are around the proteins can completely change the structure of them which is like deadly to um things like bacteria if it can actually get inside and affect it I wonder if one of the reasons it's so difficult to figure out is because even in a bacterium there's an awful lot
of chemistry going on in there and it's really difficult to unpick different biochemical mechanisms so it's probably doing multiple things and it's having these multip effects which seems to be similar to what happens in um radiation sensitization which gold is quite a common nanop particle to use there as well yeah so what happens in that case o so I read so many Journal articles about this had so many facts spinning through my mind there are loads of different
ways that gold nanoparticles can be used um as a radiation sensitizer which essentially means it makes certain cells more sensitive to radiation so the idea is that you can create the golden nanoart Les to specifically Target tumor cells and then when you undergo radiation therapy in a hospital the tumor cell is more likely to be affected by the radiation than the healthy cells oh wow yeah so some of the mechanisms involve radiation chemistry which I have a little bit of a background in so when
the gold nanop particles absorb the radiation they can then undergo all these different electronic effects that then creates lots of free radicals which as a lot of people know tend to do damage to biological structures including including DNA from a yeah know I had a bit of a flashback when you said Quantum scattering then so what is happening in with Quantum scattering because I don't know what that is Compton I not even Quantum Compton Compton is just was a physicist
and it is essentially conservation of momentum between photons and particles interacting and it's just a way that they can interact with radiation it's like used a lot in particle physics but it's really interesting to see and explain this kind of medical biophysics background which I've not seen it in that context before so if we're staying in the biological realm another application of nanop particles was using zinc oxide and titanium dioxide in sunscreen why is it beneficial in sunscreen
nanoparticles um essentially because you can apply them so thinly that they don't make you look like you just coated yourself in white pain oh interesting so it's more for athetics you could apply non- nanoparticle zinc or titanium dioxide and it would still have the same effect of protecting you from sunlight and the way it does this is to absorb and then reflect it back out absorb the UV yes the UV doesn't reach your skin it's just reflected back out by the zinc
oxide or the titanium dioxide which sounds kind of boring I mean if it works yeah there was a little bit of controversy that kicked up about 10 15 years ago I I think maybe even longer there was some suggestion that zinc oxide in particular could actually help cause cancer rather than help prevent it oh no did we find out whether that's the truth or misunderstood science in the media I think the consensus is that in the laboratory study that kicked off this
idea yeah it did seemed to have adverse biological effects but one of the studies involved like using lung cell and obviously you're not likely to expose your lung cells to sunlight your body is covered in a layer of dead skin cells and not a lot penetrates that so even if the zinc oxide was producing all these radicals similar to how the gold does in cancer therapy when it's inside the tumor the zinc oxide might be doing the same but it's not penetrating your skin whether it's producing these
radicals I'm not 100% sure actually it could do I guess if there are other things in contact with it because one of the advantages of nanop particles is they've got this really big surface area right so that can produce lots of chemical reactions potentially but no it seem seems like best advice is still to wear sunscreen I'm wearing my sun cream every day just in case even though in Edinburgh there's not that much sun but even with Cloud there is some solo radiation that is true UV can still be
quite High when it's cloudy can't it and uh one of the things the manufacturers did just in case there was an effect that they weren't aware of was to kind of coat the nanop particles in something that would help prevent any radical production so there you go they doubled down that's good cuz I I did have a concern about if silver was really good at killing bacteria what would happen to humans then and apparently that is not a concern because it's again on the surface yeah our skin is actually a
really good barrier against foreign things yeah I guess beyond what we've mentioned so silver and gold and the zinc oxide titanium dioxide when it comes to radiation therapy there are loads of different nanoparticles that you could use and the exact one that you would use depends on I think the type of cancer and the organ that it's affecting we could do many many episodes on just radiation sensitizers I think wow maybe we should move on we can maybe revisit it at some point but we've managed to
sort of like fine tune if you were going for a lung cancer we'll use these types if we're going for pancreatic we might use something else that's what I understand at the research yeah it sounds like it's like a vast field so it's like just one application of nanotechnology right there were sounds like there are lots of others yeah so when I was doing my internship the company I was working for their product was a quantum dot which is a subcategory of nanop particles they were
looking at applications in TV and lighting as well as potentially medical diagnosis and screening it kind of reached you might say a wide spectrum is that a quantum dot joke yes of applications you might want to explain that one my best understanding of quantum dogs they exhibit semiconductor properties when they absorb energy they then emit it in my case as light or maybe they could emit it in other lengths of the electromagnetic spectrum and therefore you could get something
useful out of them yeah I was actually reading a bit about it and people were comparing Quantum dots in television to LEDs so LEDs stand for light missing diode and so they're both kind of electronic components but um a quantum dot has very specific tunable Optical properties so you can make a quantum dot to kind of emit whatever light color you want and um that's why in you actually people were saying that you get much more vibrant crisp colors crisp colors
in TV when you use quantum dots compared to LEDs because they're just much more efficient and you can actually tune the property of light that you want it to emit yeah um a lot more accurately yeah so you could basically spec almost like narrow down what wavelengths you were going to emit based on the size of the particle that you've produced I think em and I have both used the term Optical properties not really defin it it's how it interacts with light isn't it that's
what I take it to mean yeah yeah I just took it as light related it just gives you the idea it's turning into some sort of tiny tiny little lens it's not quite what it does there's also the idea they can be really stable isn't this there are like lots of properties of nanop particles that give them really specific advantages which is why they researched so much for very specific applications it sounds like it sounds like they're a bit kind of the world is your oyster if you can make
something small enough is very repeatable and very producible then you can kind of have a goal in mind and try and make something that can achieve that because Optical properties of things so how much light they reflect or anything else even you know even in some cases how much light they Bend is a very desirable quality to have depending on what you're looking for so I think that's why people get so excited about nanop particles because it's kind of like I'm not going to say the stem cell
of I don't know chemistry but but it can kind of be whatever you want it to be as long as you tune it in a certain way I think is how I'm seeing all of the buzzwords around nanoparticles kind of makees sense to me and all the different applications as well I think that's a good place to to end a conversation we were learning about I I mean I was learning about what is the Quantum size effect and how that related to work that I did almost 10 years ago in a little
lab making Quantum dots we learned about the definition of a nanop particle and their uses particularly in medicine and the future is bright with with Quantum dots I think I've saw that from a TV advert but also yeah but we know that they work and we could make them do all sorts of things with electromagnetic radiation the views expressed in this podcast belong entirely to the person that said them they did not represent into any industry or organization if you
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