A team of Johns Hopkins engineers has created a new, more powerful way for observing molecular vibrations, a breakthrough that could have far-reaching consequences for early disease diagnosis. The study was published in Science Advances.
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The team, led by Ishan Barman, a professor at the Department of Mechanical Engineering, was the first to demonstrate how light can be utilized to form unusual hybrid states with molecules, allowing even the smallest vibrations to be detected more clearly and precisely.
In healthcare, this novel approach of identifying molecules might lead to earlier and more precise identification of disease biomarkers in blood, saliva, or urine. However, it could have broader medical applications: in pharmaceutical manufacturing, it could enable real-time monitoring of complex chemical reactions to guarantee product consistency and safety; and in environmental science, it could allow for unprecedented trace-level detection of pollutants or hazardous compounds.
Molecular vibrations (the small, distinctive motions of atoms inside a molecule) provide chemical “fingerprints” that can identify the existence of diseases ranging from infections and metabolic disorders to cancer.
To find these vibrations, scientists frequently employ methods like infrared and Raman spectroscopy. However, these approaches have serious drawbacks: the signals they rely on are frequently weak, easily obscured by background noise, and challenging to separate in intricate biological environments like blood or tissue.
We were trying to overcome a long-standing challenge in molecular sensing: how do you make optical detection of molecules more sensitive, more robust, and more adaptable to real-world conditions? Rather than trying to incrementally improve conventional methods, we asked a more radical question: What if we could re-engineer the very way light interacts with matter to create a fundamentally new kind of sensing?
Ishan Barman, Professor, Department of Mechanical Engineering, Johns Hopkins University
By creating an optical cavity with highly reflecting gold mirrors, the team was able to capture light and “bounce” it back and forth, improving its interaction with the molecules within. The molecular vibrations and the restricted light field become so entangled that they create whole new quantum states known as “vibro-polaritons.”
The team was able to accomplish this feat using a standard setup, without the need for high-vacuum, cryogenic, or other severe environments that are generally necessary to sustain delicate quantum states.
According to lead author Peng Zheng, an associate research scientist in mechanical engineering at Johns Hopkins, this study outlines how to transform “quantum vibro-polaritonic sensing” from a concept to a functional platform, which could lead to a new class of quantum-enabled optical sensors.
Rather than passively detecting molecules, we can now engineer the quantum environment around them to selectively enhance their optical fingerprints by utilizing the quantum vibro-polaritonic states.
Peng Zheng, Study Lead Author, Johns Hopkins School of Medicine
This study marks a meaningful advance in the emerging field of ambient-condition quantum technologies, leveraging quantum principles in a novel way, without relying on the traditional infrastructure typically required. Finally, Barman envisions small, microchip-sized devices that might incorporate quantum technology into portable point-of-care gadgets and AI-powered diagnostic approaches.
The National Institute of General Medical Sciences funded this study. Steve Semancik, a physicist at the National Institute of Standards and Technology (NIST), co-authored the study.
Journal Reference:
Zheng, P., et al. (2025) Quantum vibropolaritonic sensing. Science Advances. doi.org/10.1126/sciadv.ady7670.