.png) |
| A future hybrid system could deploy these locusts to detect chemical vapors in search-and-rescue operations or war zones, quickly identifying particular chemicals based on neural response signatures in the organism and pinpointing their locations before responders enter the scene. The foam on the antenna and wing can enhance an organism’s innate sensory system, collect samples, and detect trace chemical signatures. Photo Credit: Raman lab |
The Core Concept: A hybrid chemical sensing approach that augments the innate olfactory system of locusts with a surface-enhanced Raman scattering (SERS) substrate—specifically, a highly porous collagen foam—applied to their antennae and wings to improve trace chemical detection and sample collection.
Key Distinction/Mechanism: While living insect olfactory systems are extremely sensitive but limited in the breadth of compounds they can identify, and synthetic sensors are highly accurate but lack biological nimbleness, this system merges both. The ultralight nanomaterial coating boosts signals from targeted molecules (including TNT) without impairing the insect's natural sensory or physiological functions, allowing the biological and artificial systems to complement each other.
Major Frameworks/Components:
- SERS (surface-enhanced Raman scattering) substrate techniques for boosting molecular signals on nanostructure metal surfaces.
- Plasmonic nanomaterials utilized as an ultralight collagen foam.
- Integration with biological insect olfactory receptor neurons (specifically in locusts, which possess roughly 50,000 such neurons per antenna).
Branch of Science: Biomedical Engineering, Mechanical Engineering, Materials Science, Biology, Chemistry.
Future Application: Deployment of augmented insects in search-and-rescue operations, disaster zone mapping, and the detection of chemical weapons or explosives in field environments.
Why It Matters: It successfully demonstrates that biological organisms can be harmlessly integrated with synthetic nanomaterials to create superior, dual-modal sensing systems capable of both high-sensitivity broad detection and highly specific chemical identification in challenging environments.
.png) |
| The antenna of a locust in Barani Raman's lab is equipped with collagen foam containing nanomaterials that can detect and collect trace chemical signatures. Raman and colleague Srikanth Singamaneni, at WashU McKelvey Engineering, developed an approach that combines biological sensing with synthetic collection techniques, allowing for precise identification of certain compounds. Photo Credit: Raman lab |
Scientists have long explored the idea of using insects as agents in the field in places where humans will not fit or survive. Imagine a cockroach in an earthquake zone, able to skitter into the rubble to map exactly where human chemical signatures can be found, or a grasshopper leaping through a minefield to bring back a map of the bombs based on the vapors it encountered. Recent research from Washington University in St. Louis brings this science fiction concept one step closer to reality.
“We marry the best biology has to offer with engineering principles to create a superior sensing system,” said Barani Raman, the Dennis and Barbara Kessler Professor of Biomedical Engineering at the WashU McKelvey School of Engineering.
Raman and his colleague Srikanth Singamaneni, the Lilyan and E. Lisle Hughes Professor of Mechanical Engineering and Materials Science, are senior authors of the research published in the journal Advanced Materials. The study describes a hybrid chemical sensing system combining an insect’s natural sensing abilities with nanomaterials to help collect and identify chemical samples.
Both biological and artificial chemical sensing systems have drawbacks, Singamaneni said. A locust’s olfactory system is extremely sensitive and can detect faint odors that guide its behavior. However, even with 50,000 olfactory receptor neurons in each antenna, it cannot identify a wide enough range of chemical compounds. Meanwhile, synthetic sensors do not perform as well as nimble living creatures, but they can be highly accurate at detecting specific compounds. Why not combine the two?
“Both biological and artificial chemical sensing approaches have their strengths and drawbacks,” Singamaneni said, but by combining them, “you can cast a broader net.” Here, researchers added an ultralight, highly porous nanomaterial coating, known as a surface-enhanced Raman scattering (SERS) substrate, to the locusts’ antennae.
SERS is a technique that boosts signals from molecules on or near nanostructure metal surfaces, and it is especially useful for detecting trace chemicals. In this case, researchers used a collagen foam applied to the antennae or wings. The foam augmented the insect’s odor-detecting skills without interfering with its other functions.
Singamaneni’s laboratory specializes in designing and synthesizing these types of nanomaterials. He has been working with plasmonic nanostructures for as long as Raman has been mapping locust sensory circuits. They melded their research, and it yielded significant results. Locusts equipped with the foam outperformed non-SERS locusts, as well as synthetic chemical sensors, improving odor-detection performance across all chemicals tested, including the chemical signature for trinitrotoluene (TNT).
In a series of tests, the hybrid systems successfully detected a wider range of odors without affecting the insect’s normal functions.
Raman said a key challenge in chemical sensing is that researchers often do not know what molecules they are targeting. The foam attached to the antenna helps identify particular chemical species, he noted. The biological and chemical sensing components complement each other.
“It clearly showed the best of the two worlds can be merged,” he said.
Funding: Research supported by the Air Force Office of Scientific Research (FA95502310461) and the National Science Foundation (CSE-2319060, CBET-2331330).
Published in journal: Advanced Materials
Title: Plasmonic Foam-Enabled Dual-Modal Biohybrid Chemical Sensor
Authors: Avishek Debnath, Prashant Gupta, Rohit Gupta, Yixuan Wang, Yin-Yuan Huang, Feiyang Deng, Ramachandra Reddy Atigadda, Shantanu Chakrabartty, Baranidharan Raman, and Srikanth Singamaneni
Source/Credit: Washington University in St. Louis | Leah Shaffer
Edited by: Scientific Frontline
Reference Number: eng101926_01
