🌟 Harnessing Light at the Nanoscale with Sara Hernandez Mejias: Episode 192 of Under the Microscope 🔬

What to Expect:

In this episode, Sara Hernandez Mejias discusses her innovative research on light conversion and its applications in photochemistry and nanophotonics. Sara shares her journey from studying physics in Spain to working in molecular biology and spectroscopy across Europe, and her work on designing photosystems to harness light as an energy source.

About the Guest:

🌟 Key Takeaways from This Episode:

• Light Conversion: Designing photosystems to optimize light as an energy source for different applications.
• Career Journey: From physics in Spain to molecular biology and spectroscopy across Europe.
• Favorite Experiment: Combining molecular biology with spectroscopy to tune light conversion pathways.

🔬 In This Episode, We Cover:

Sara’s Research:

Sara’s research focuses on designing photosystems that harness light as an energy source. By tuning these systems, she aims to optimize light conversion for various applications, including photochemistry and nanophotonics. Her work involves creating and analyzing models to simulate light conversion mechanisms.

Sara’s Career Journey :

Sara’s academic journey began with a Bachelor’s in Physics in Spain. She pursued her passion for interdisciplinary research, leading her to molecular biology and spectroscopy across Europe. Her diverse experiences have enriched her research perspectives and expertise.

Sara’s Favourite Research Experiment:

Sara’s favorite experiment involves combining molecular biology with spectroscopy to tune light conversion pathways. By embedding specific molecules in proteins and tuning their structure, she can selectively control light conversion processes, enhancing the efficiency of these systems.

Life as a Scientist- Beyond the Lab :

Sara values the collaborative nature of scientific research and enjoys engaging with the global scientific community. She is passionate about teaching and mentoring the next generation of scientists and values the international experiences she has had throughout her career.

Sara’s 3 Wishes

1. Increased funding for research: Sara wishes for more financial support to advance innovative research projects.
2. Greater collaboration between researchers: She advocates for stronger partnerships to enhance knowledge sharing and collaborative efforts in research.
3. Improved public understanding of scientific research: Sara emphasizes the importance of public awareness and support for scientific advancements.

Sara’s Time on @RealSci_Nano:

Sara will be taking over the RealSci_Nano Twitter account to share her research on light conversion and its applications. Followers can expect to learn about the innovative techniques and systems her work focuses on, as well as insights into her interdisciplinary research journey.

Transcript

[00:00:00] Hi everyone, I’m Pranoti, host of Under the Microscope. This series is brought to you by the Real Scientists Nano team. Our goal is to provide a platform where scientists can communicate their work and interact with the public. With that in mind, every week we introduce you to a scientist working in the field of materials or nanoscience, who tweets from the Real Scientists Nano Twitter account.

Which is real site on the scroll nano. Hi

everyone. My name is Pranoti. I am your host of the end of the microscope series, podcast series, vodka series, and today we have a very, very special guest with us. Uh, Please welcome Sarah Hernandez Mirjeas. I hope I pronounced that correctly. Um, Sarah is a senior researcher [00:01:00] at the Madrid Institute of Advanced Studies in Nanosciences.

Um, of course in Madrid, in Spain, in Europe, which is on Earth. Um, and Sarah also recently joined the Real Scientist Nano Team, the Science Talk and the Real Scientist Nano Team. So welcome, Sarah. How are you? Thank you. I’m fine. Happy to be here and arresting this podcast is also very special for me. So thank you for inviting me.

Of course. We are very happy to have you here. So let’s dig in. Um, could you explain your research to us in super simple words, please? Mm-Hmm. . So, uh, I do mainly research in light conversion and, uh, trying to use light as an energy source. Mm-Hmm. . So basically what I’m doing is design a photo systems that I can tune on.

Demand Mm-Hmm. , and try to optimize them just to harness the power of the light as an energy source for different applications, including [00:02:00] photochemistry. Nano photonics depends on the system that I built. Ahuh. Wow. Oh, wow. Wow. That sounds so cool. Okay. I have so many questions. Um, so how, how, how did you get to, uh, be the senior researcher like now the research that you’re doing?

Could you tell us a bit about your research journey, like the career journey so far? Mm hmm. So, um, I am physicists and I am very proud of being physicists, but also I’m very interdisciplinary. So when I finished my, my bachelor, I just needed to choose a path and I decided to do a PhD. And I heard about new materials and biomaterials.

So I just, uh, decided to go there. And it then that’s been very, very much molecular biology. So very far from anything that I study in my bachelor. So it was a big day, um, a big shift. So I did all my PhD in protein design and I was building nanosystems with, with cool tone and the nanoscale and depends on the [00:03:00] nanostructure, they change the macroscopic properties.

So after my PhD, I, so I enjoy a lot learning this molecular biology part, but I really felt that I, I wanted to know more into mechanistic studies and this kind, so not only build the material, but also study the mechanism. So I decided to proceed with the postdoc, but now more focused in time resolved spectroscopy, which is a technique study.

that allows you to know a bit the light conversion mechanism in systems. So I did a postdoc of six years now, so quite a long postdoc already, in laser spectroscopy and time resolved spectroscopy with different systems. And now recently I’m super happy because I get this grant Uh, around as a junior leaders tips.

I will start my own group in October, combining this both world more the molecular biology and spectroscopy in one team. [00:04:00] So we are going to be working in in this light conversion mechanisms in engineer with engineer photo system based on proteins. So it’s very nice. And it’s good. Yeah, related with the with this journey is very interesting to me something because when I finish my bachelor.

I was considering to be a nuclear physics, so I really was into nuclear physics. But then I said, um, this sounds very cool, but also it sounds like you are going to be abroad. In, uh, in different countries and everything, and I was not feeling ready for that, and I was a bit naive because then I’ve been in Sweden, I’ve been in the Netherlands, and really I’m very happy that I had this super international journey, that I met many people of different countries and I really learned a lot.

But there’s something also curious from the yard and how you make decisions depends on what you feel that is going to be about, but then it’s [00:05:00] completely different. Yeah, absolutely. That’s that’s really interesting that you wanted, you considered being a nuclear physicist, but then you decided against it, but then ended up.

Yeah, I mean, it’s it’s it’s amazing. So, um, about your current research with the, uh, with the spectroscopy and the molecular biology like the molecules, Um, are there any specific molecules that you are working with? Or is it like the whole range like? At the end, I would like to know what is your favorite molecule if you’re working with a few.

That’s where I’m headed here. So I’m working mainly with organic dyes. So these dyes are made by aromatic rings. So the, um, depends on the how many aromatic rings they have, they have, these electrons are like moving around all the molecule. So depends on the, on the structure, you can have different absorption properties.

So I don’t have any favorite molecule because I use depending on, so depends on what system I’m using and depends on the application that I want to go, I use in different molecules. For example, I use both DP. Uh, this is kind of molecules that I’m using that is. It’s very [00:06:00] interesting because you can tune.

The structure to have a different like to have different properties, but also one of my favorite now is firing molecule. This is done by four benzing groups. That is the one that I’m working with now. This is very interesting one, because when you excite your molecule to the excited state, then have different decay pathways.

So now we are just. making proteins in order to tune this pathway selectively. So I will say BODP and pyrin, perhaps for now, but let’s see in the future. So you do have favorites. Okay. Okay. So, so if I understand this correctly, if I understand you correctly, So there are these molecules or like a bunch of molecules and then you shine laser on them and whatever comes out or comes back or comes out is what you’ve studied.

That’s the spectroscopy part. Is that a fair way of saying it? And then of course it’s more complicated but if we have to oversimplify, there’s a molecule you shine laser on it and then see [00:07:00] what happens. Yeah, that’s that’s it. So what you would basically with the laser is you, you excite your molecule. So this molecule takes the energy of the laser.

So it goes to excited state and is from there. So the light conversion is basically converting the light, this light that is reaching the molecule to another state. It can be electrons or it can be a photon with another energy. So what you observe is how from when you excite your molecules is how it’s converted.

voice during time until they enter step. So you are. You are able to see these processes and you can be so I work with different lasers. One of them is in the fence or second range, so it’s really taking one second and dividing one billion one billion times, so it’s like quite fast processes. And then I have another one.

So I have another laser in the nanosecond range. So it’s just a 10 power to minus nine seconds time. So you work in this as a range time. Aha. So what happened? So with the femtolaser, which is 10 to the [00:08:00] power minus 15 seconds. So one divided by a billion, one billion. Of, uh, of, of, of second. With that, you would be able to understand that’s, that’s where the time resolve part comes in.

Like what happens, uh, on a femtosecond level in the molecule. Mm-Hmm, . And with the nano laser, it’s like what happens on a nanosecond level? What, what does this happen? How do the, how does the molecule react? Or what happens to the molecule? So that kind of information. Right? Yeah. The thing is that you have some processes that are very fast.

So, for example, uh, all the, um, the relax, thermal relaxation in the, um, all the thermal relaxation in the molecule, also things that happens intramolecularly and interacts very quickly with the proteins. This happened in the femtosecond time scale. So, it’s very quick processes, but there are other processes that, for example, rely on On interaction, like diffusional processes, for example, this kind of things that are slower because you are not already in the molecule, but you are interacting with different molecules.

This kind of things requires time. So it’s [00:09:00] it’s faster still comparing with our life because it’s nanosecond, but it’s it’s a slower processes. So you can define all these two processes like things that happen in the two rings of time. That is so cool. Oh my God, that is so cool. Wow. Oh my God, that is so cool.

Okay, so now I want to ask you this because you work with molecules, you work with lasers, you work with these super fancy lasers. How do you do that? But before I ask that, which lasers are we talking about here? Are we talking about green, red, blue, or is there like a range of, uh, lasers? So, uh, our laser generates, um, a light, uh, in the infrared, so 1075 or something like that, but then you can tune this one.

So you have your fundamental, but then you depends on, so usually when you have a light, you have also different harmonic. That you can just tune a with a sun crystals. So there are some crystal that are not that has are called nonlinear crystals. So you can, you can choose the fundamental, the first harmonic, the second harmony.

So you can go from a [00:10:00] one, this one in the fundamental, then choose also, for example, um, Around 532, uh, so this is more in the visible part, and then go for the UV, for example, 355 nanosecond. So this is basically the light that you can achieve from the laser. But then we have also a very different systems that are composed by the laser.

Um, and this is what we do. We combine crystals by different combination of crystals that allow us to convert this light in any light that you want in the visible range, UV range and infrared. So any light that you need, you can, so any light that you need to pump your molecule, you can achieve with this kind of system.

They are called OPOs, NOPAS, this kind of. So they are combination of crystals. Um, and that’s just basically depends on how they interact with the light. They convert a wavelength to another wavelength. And you can tune them to achieve the white line that you have, because, of course, so there are some molecules absorbing in the UV, there are other molecules [00:11:00] absorbing in the visible, there are other processes that you want to know that absorbs, for example, in the infrared, so you want to have a range, um, of, of lights to prove it.

Yeah, okay. Okay. Wow. That sounds so good. Because during my PhD, I think I worked with a red laser. No, did I work? I think I work with blue and green. So 488 and 532. I think 532 is green, not blue. I get confused now. Wow. Yeah. I should remember these things. It’s very interesting because you can’t really, so I, so when I was learning about lasers and this kind, so this kind of, uh, tuning.

That is a really, really interesting and there are the problem is that sometimes they are not very efficient because you have a lot of lost in each crystal. So you put many combination of crystals. If you really need to tune your, your, uh, light, you need to put, uh, a lot of combination. You lost a lot of power.

Mm-Hmm, , sometimes you need higher power. So there is a lot of research on these kind of materials that tune the laser, uh, lights and these kind of things. For example, in my group, there are some people working in the, in lac. So they do, for example, [00:12:00] different cavities that can have these different laser properties.

So like this, you can have more tunable lasers. And it’s very relevant for, for example, for me that I want to understand other kinds of systems. Right, right. That makes complete sense. Wow. So it sounds to me, Sarah, that you have been involved in a lot of interesting research projects or experiments. Um, if you have to pick one research project that you’re most proud of.

Would you pick one and explain it to us in simple words in the section we call in other words? So I would choose the one that I’m working now. Indeed, now I’m not in Spain, I’m in Sweden now, just finishing that project, so it will be published soon, I hope. So in this project, so what I like in this project is that is the first time that I really mix the molecular biology with a spectroscopy.

So basically what we have is this firing molecule that I was talking about. [00:13:00] So we imbedded this, this, uh, firing molecule in a simple protein, this protein we can tune like at the nanoscale because we know exactly the structure and the what amino acids we can tune. So what we observe is that Just tuning a single amino acid in the protein.

We can induce a sun a quadruple that interaction. So these are electrostatic interaction in order to tune the structure of the protein. So just when I’m, you know, acid tunes. Completely the structure of the protein. And then we can do a selective light conversion. So going for example, to have more, uh, chart states.

So this ping one is ke excited it case with three different pathways. One is forming electrons like chart states. Another is forming. Uh, one is spin state, different from the excited state. So it’s the triplet state and another is just emitting fluorescent. So what we observe, so. In the planner molecule, this conversion is not selective, [00:14:00] so it can go, it has a quantum gel, uh, for each of them.

So you are losing energy. Imagine that you want electrons at the end. You are losing energy there because you have also the other path. So with the protein and tuning the structure, we can select a one path or another. So February, for example, charge formation forming, uh, uh, fluorescent or forming the triple test state.

And it’s very cool, I think. It is. Yeah. It sounds really, really cool. So this was a project that is in Sweden you mentioned? Mm-Hmm. . Okay. So yeah, I started here. I, I think here two years as a postdoc. And I started here, this project, it was, um, yeah, I started here, uh, the project and now I, we are finishing and I will.

Um, and I really follow my career path through that path of modifying proteins to do selective like conversion. So the idea started here. That is so cool. So you must be really, really proud of this. Mm hmm. I really like it. I hope it will be published soon, uh, so that we can all read it. Would you be able to talk about it a bit when you are taking over the Twitter account?

Uh, repeat again, please. Can you, would you be able to talk about this project when you’re taking over the Twitter account as well? I know the research is not published. Ah, I think that is fine. That is fine. [00:15:00] Okay. Okay, that’s cool. That’s really cool. So, Sarah, um, I mean, research is one big part of being a scientist.

It is. But what else do you like about being a scientist other than the research itself? So one thing that I like is that, uh, so, okay, you can really do research in things that you like it, right? But I like to do it with a team. So one thing that I like is that you can choose what person you want to involve in your team and work together in that project that you like it.

So this is one thing that I like it. Also, so I, I really like to do this networking and all this international environment that we are exposed on when you are in, when you are a scientist, that perhaps if you are working in a small company in Spain, you have not. And you’re really, I think that it really enrich you as a person to be in this international environment.

Right. And I think that this is my, my main favorite thing. So building a team and this international environment. [00:16:00] That’s really cool. And I hope you will soon be able to start like you will be able to start building your team. I’m super excited for you about it, about that part of your career and that part of your personality as well.

Um, Sarah, I hope your research experience has been wonderful and will continue to be wonderful in the future as well. I mean, it sounds to me that It’s worked out very well for you. Uh, and also congratulations. It was challenging, but, uh, of course, yes. So regarding the challenges, um, if you had three wishes to improve your research experience, what would you ask for?

And I’m not promising anything, sorry. So. I think that, um, one thing that I would like is to invest more time with people that inspired me. So sometimes the researchers don’t have time, like senior researchers don’t have time to talk with you and these things. But I, I would like to have more time to sit with them and just discuss about.

Research, but also about life life. I mean, also what path they chose. So have this this kind of conversation with with people that I consider that are inspiring. So this was the first thing. [00:17:00] The second thing that I will ask will be. So now I start to do networking, but I would like to have the chance to network more because I really enjoyed this collaboration.

I think that they are really important part of the research also, like having a collaboration that we can, you can put all expertise together. So I would like to have a bigger network, uh, working on that still. And then the third thing, I think that I would love to have a stable funding forever. So this will be my three wishes.

Uh huh. Okay. Okay. So to be able to speak with people, uh, that inspire you, um, stable funding. I think that’s, that’s, that’s just, yeah, that’s very, very, very important. And more opportunities to network. That sounds, that sounds amazing. Um, and I’m sorry. I’m sorry. Not say. Yeah, no, I was just saying I these are quite realistic wishes, to be honest, Um, and I hope they will come true soon enough.

Um, Sarah, this has been wonderful talking to you, learning about your research, learning about you as a person, as a scientist. So what can the [00:18:00] followers expect in the week that you will be taking over the Real Scientists Nano Twitter account? Can you repeat the question? Um, what can the followers expect in the week that you are taking over the Twitter account, the Real Scientist Nano Twitter account?

So, uh, you mean what, um, what they are going to flag? Yes. What are you going to tell us about when you are tweeting from the account? Uh, so I think that they, uh, This one I, um, about your research, about your career, about your papers, um, about, yeah. Okay. So yes, in my Twitter account, yeah, I, they, they will know about my, my research, about, um, my career a bit.

Also, I tweet a lot, some advices, uh, for young people and also some wishes, uh, used to, I used to tweet about some wishes also. So I like the, I think that this one. Okay. That sounds cool. And I hope that we will get some nice pictures from your lab and from your institute and from Madrid as well. It has been my wish since a long time to visit Madrid and lots of other parts of Spain as well.[00:19:00] 

So, um, yeah, I look forward to having you on Real Scientists Nano. Thank you very much, Sarah, for speaking with me. Thank you for hosting me.

Thank you for listening. This is Pranati, host of Under the Microscope. To know more about us, visit our website, thesciencedoc. com, and follow us on Twitter at realsci underscore nano.

Podcast title: Harnessing Light at the Nanoscale

Sara is a Researcher at IMDEA Nanoscience, Spain.

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