Threat Detection Biosensors and Bunny Suits

Welcome to Science at Work, a new podcast from Savannah River National Laboratory in Aiken, South Carolina. I’m your host, Mike Ettlemyer. Science at Work is a production of the Savannah River National Laboratory, SRNL, Office of Communications. This year is a special one for us. It’s been 20 years since the U.S. Department of Energy designated SRNL as a national lab, but our legacy spans seven decades to back in the early 1950s and the Cold War.

Some of our listeners might not know very much about what a national lab is or what it does. We hope to change that by interviewing the scientists, engineers and other professionals who are at the heart of who we are and what we do.

Today, we’ll speak with Steven Demers, a physicist and staff scientist in the Nuclear Effluent Analysis Group. Steven’s research involves working with sensor materials using spectroscopic techniques. Why is this important? Well, Steven will enlighten us with the details, but the bottom line is that threat sensors enable first responders to save lives.

I became interested in speaking to Steven after his three-minute pitch about his research. It was a TEDx-style talk he gave in 2023 during SRNL’s first Research SLAM. He not only did a great job, but he also won second place in that competition. Before we get into Steven’s research, let’s get to know him a bit.

Thanks for joining us today, Steven.

Steven Demers: Thanks for having me.

Mike: Great to have you here. Where did you attend college and what did you study?

Steven: Yes. So, I did my undergrad at Duke University, studying physics, and then moved into my Ph.D at Rice University. At Duke, I was in the Finkelstein Lab, where I worked in creating DNA origami nanostructures for precise placement of nanomaterials with very high precision. At Rice, I kind of continued this line of research, and I was mentored by Professor Haffner, where the group was focused on using a new technique in order to determine molecular orientation and lipid bilayers.

So, kind of for my Ph.D work, it was figuring out how cholesterol orients itself in cell membranes.

Mike: I’m very familiar with cholesterol, being of middle age. What brought you to SRNL?

Steven: So, I was brought in as a postdoc for chemical, biological and radio nuclear detection — CBRN. We were creating a biosensor, as part of an LDRD, that aligned very well with my previous work, both in undergrad as well as grad school.

So, undergrad, I had worked with DNA materials, and that was used as a basis for our biosensor combined with our nanomaterials for my Ph.D work. It’s kind of like a match made in heaven. You know, I could combine all of what I learned for grad school and undergrad in one particular project that had very real-world applications.

Mike: Ah, very cool. What is the Nuclear Effluent Analysis Group here at SRNL, and why is it important?

Steven: Yeah. So, the Nuclear Effluent Analysis Group focuses on the fate, transport, collection and detection of trace effluents from nuclear facilities to make sure everything is as expected from both an operational and environmental standpoint. We really don’t want any nuclear waste getting into environments or streams or anything like that.

And this group overall is part of the nuclear nonproliferation division here at SRNL, a part of the global security. As the name implies, we work on the nonproliferation of nuclear materials. The specific team I work with is the nuclear effluent R&D group. And it’s focused on creating new technologies for detecting these nuclear effluents at very low concentrations.

The current focus is looking at environmental monitoring, for nuclear effluent from SRNS and similar Department of Energy sites, kind of to reduce their impact for some of these nuclear processes, that they have on the environment, like clean up old waste as well as reduce, new produced waste.

Mike: Okay. Now the Nuclear Effluent R&D. Do you call yourself the nerd group by any chance?

Steven: Yes, we do.  

Mike: I thought you might.

Steven: We always like to have fun with our acronyms if we can.

Mike: Why not? We have so many acronyms here.

You’re listening to Science at Work, a new podcast from Savannah River National Laboratory. We’re speaking with Steven Demers, a physicist at SRNL who works in the Nuclear Effluent Analysis Group.

Steven, we’ve been very interested in your research. Please tell us about your work with sensor materials and how your research might impact our listeners.

Steven: So, kind of to begin with, CBRN threats, that stands for chemical, biological and radio nuclear threats. These pretty much can inspire all means of threats that you’ve probably heard of in the news or any other like dramas or series.

And the project I was working on is creating a biosensor that would hopefully simplify and hasten the detection of these threats in field. The CBNR biosensor has just two components, different light emitting nanomaterials that are connected by very specific DNA strands. Picture a kind of star or sea urchin type design, but very, very small. So, on the nanometer scale.

Mike: Wow.

Steven: And these DNA strands are created to only bind to one particular threat. And so, we know very high specificity. We know it’s only going to be that one threat with very high accuracy, which is what we need in the field. So, when these threats do bind, these biosensors emit a light corresponding to that particular threat. For example, red for anthrax, green for sarin or maybe yellow for uranium, you know, so you have very specific color channels.

Mike: Right. So that would be very helpful in determining what that threat might be.

Steven: So, we might have seen on TV and like a dramatic scene where an envelope is opened, and this mysterious white powder comes out. The actor actress kind of convulses or something like that. And bad things happen, right? But sadly, these scenes are kind of grounded in reality. And these are called white powder scenarios where a mysterious white powder is found in an envelope. And they can be, in fact, very dangerous. Probably the most high-profile example was from the 2001 U.S. anthrax attacks, where anthrax spores were released into mail sent to news outlets as well as senators.

Mike: I remember that very, very well back in 2001, even though, well, it seems like a very long time ago now, but, yeah, that was a big story.

Steven: So, current detection methods, you need several different devices in order to determine kind of what that white powder is. Is this anthrax spores? Is this ricin toxin? Is this sarin or is it just cooking flour, and somebody is just pulling your leg, you know, you don’t know. You always gotta go for the worst-case scenario and prepare for that.

So, first responders and the large positive pressure suits. So, you know, like those giant bunny suits. Very hard to move around. And they don’t want to be in there. They want to make sure they get in and out and test for these particular threats very accurately. So, we are hoping to reduce the time and as well as the limit of detection for these threats using this biosensor system. You might know in the airports, go through security, your bag, it has to get checked.

There’s like, sir, please step aside, we have to check your bag. You know, so that infrastructure for detecting threats is already there. So, if we have a similar technology that kind of mimics that but has a wider net of potential that we can detect. That would be very useful for making sure everybody’s a little bit safer.

Mike: Right, right. Ok. That’s very interesting. What can you tell us about the future of this research? And, you know, what would you say is next?

Steven: Yeah. So, for the future, it’s kind of, for this biosensor work, it’s kind of split into three different thrusts per se. So, we have a proof of concept already done.

The first stage was looking at a nerve agent metabolite. So, if somebody was exposed to a nerve agent, how the body gets rid of that chemical is through this metabolite. So, we did that, with the sarin metabolites, methylmalonic acid. And we’re like, ok, this works. The proof of concept. Let’s move on to the b in CBRN, biological.

Probably the two most infamous ones are anthrax and ricin. So, hopefully doing this whole rigmarole for detecting a biosensor or creating a biosensor for that detection.

Mike: Ok, yeah. I don’t mean to interrupt, but I’m just listening with utter fascination because, you know, we’re used to seeing, with airport security, different devices being used, but we don’t know a lot about how this, how these things come into being. And so the research that you’re working on sort of enables those, those end user cases. Right? I mean, not to say that what you’re doing is specifically related to airport scanners, but what I mean is, you know, it’s just very, very important research to keep us safe.

Steven: Yes, exactly. I don’t know too much about how the airport scanners work. I don’t know if I could even discuss it in the open air.

Mike: Sure, sure.

Steven: But yeah, just using that infrastructure because everybody’s like, oh, yeah, they do the swipe on your luggage and they’re like, oh no, you’re fine. Just go on, shuffle your bag together and then go on through the airport, you know?

Mike: And that’s always fun.

Steven: Oh, yeah. So much. But kind of then for the biosensor, second portion would be kind of going to the radionuclear side, which is a little bit more interesting because you can’t have like, safe surrogates. And surrogate is kind of a similar but different molecule that doesn’t have as bad of a response in the body if you’re exposed to it.

Because I know for one, I don’t really want to work with actual anthrax spores right off the bat. You know?

Mike: Maybe you work your way up to that.

Steven: Yeah, you got to work your way up a little bit. So, kind of similar for a rad/nuc, safer isotopes first and then go into the radionuclear ones.

Mike: Yes, yes.

Steven: And then kind of like a final one, working with my friend, Chris here. We’re hoping to use, combine microfluidics, to create an in field type device that would use very little amounts. So, just like a single spec or something like that of a white powder instead of like a whole container.

Mike: So, it would essentially make it, I guess, easier to test and quicker to test, versus other methods that are out there? Okay.

Steven: Yes.

Mike: Yeah, that seems great to me. And you mentioned Chris. So, is he in your group?

Steven: Yes. So, he was a postdoc with me here. Got along well, go to trivia every Wednesday with the rest of my cohort of postdocs. It’s been fun.

Mike: So, there you go. Excellent, excellent. Alright, well, you know, in addition to getting to know you, as the scientist and your work here at SRNL, what do you like to do for fun? Away from work.

Steven: So, usually after work, kind of get the stress out of the day, you know, the anxieties. I just go to the Greenway, in North Augusta and usually run a 5k around the SRP park area. On the weekends hoping to get back into hiking, enjoying the nice spring we’re having right now.

I like to read different novels, mostly like fantasy, sci-fi kind of thing. Or watch different shows on Netflix or what have you, you know. And finally, I kind of like to travel around. I just got back last week from Austin, Texas, where I saw the eclipse. That was with a bunch of my grad school friends. And that was an experience I didn’t realize it was on my bucket list, but now I’m glad I can check that off because, man, it was breathtaking seeing that, nice experiencing that.

Mike: I saw when we had the, I guess the full eclipse here in South Carolina in 2017. And that was a sight to behold.

Steven: Yeah, because I saw the kind of like partial version of that at Rice. And it’s very interesting, going under like a branch or a path of trees and seeing like, all these little, half-moon shadows. A very surreal, really cool phenomenon.

Mike: Yeah, yeah. So cool. And then you were mentioning earlier you’re going to head down to Florida, maybe the Kennedy Space Center.

Steven: Yes, yes I am. I grew up at Merritt Island. On the northern part of Merritt Island is Kennedy Space Center.

Mike: Yeah, the Space Coast.

Steven: Space Coast. Yeah, 321 area code.

Mike: The reason I would know that is, I have a buddy who works for KSC, and he’s been there for over 30 years. And I was just there last month and got a personal tour of some things. And it’s a special place.

Steven: Yeah, every time I go there I’m always like, wow, this is so cool. And I guess I’m pretty close to it. You know, I’m in the science field. I hope that maybe my sensor can go up in a rocket or something in the future, you know, because, man, that would be cool. We just built that, look, it’s working, but we’ll see.

Mike: Yeah, that would be very, very cool. Well, Steven, we really appreciate your time today. And thanks for sharing your expertise with us and joining us. And thank you all for listening to our podcast. Science at Work is a production of the Savannah River National Laboratory.