A newly developed hydrogen sensor made from an organic semiconductor delivers fast, ultra-sensitive detection under ambient conditions while consuming minimal power.
Study: A robust organic hydrogen sensor for distributed monitoring applications. Image Credit: MT.PHOTOSTOCK/Shutterstock.com
Published in Nature Electronics, the study details a low-cost, long-lasting sensor that offers high sensitivity, rapid response times, and reliable operation in everyday environments, addressing key limitations in existing hydrogen detection technologies.
Background
Hydrogen sensors are typically based on one of several detection mechanisms: resistive, capacitive, optical, acoustic, or magnetic. Among these, resistive sensors are particularly attractive due to their straightforward design, scalability, and ease of integration. However, traditional resistive sensors often depend on metal-oxide semiconductors or noble metal contacts, which usually require high operating temperatures or significant power input.
Organic semiconductors offer an appealing alternative, thanks to their tunable electrical properties, compatibility with solution-based processing, and low manufacturing cost. While earlier attempts using materials like polypyrrole and pentacene have shown some promise, they’ve struggled with slow response, poor stability, or limited sensitivity.
This new work builds on the insight that ambient oxygen naturally p-dopes organic semiconductors, enhancing hole transport. When hydrogen is introduced, it disrupts this doped state, reducing carrier density and current. This reversible de-doping effect forms the foundation of the sensor’s functionality.
Sensor Design and Testing
The research team developed the sensor using an organic semiconductor known as DPP-DTT. They began by patterning interdigitated platinum electrodes onto a substrate using lithography. The DPP-DTT layer was then applied using spin-coating or screen-printing methods that allow for scalable, cost-effective fabrication.
To test performance, the sensor was integrated into a gas flow setup that enabled precise control over hydrogen concentration, temperature, and humidity. Electrical measurements were taken by applying a bias voltage and monitoring current changes in response to hydrogen exposure. The researchers tested a wide range of hydrogen concentrations—from parts per billion to thousands of parts per million—under ambient conditions of roughly 20 °C and 50 % relative humidity.
They also evaluated the sensor’s long-term stability, tracking its performance over 646 days to simulate real-world usage. In addition to lab tests, the team demonstrated the sensor in practical settings: detecting hydrogen produced during water electrolysis, monitoring accidental leaks in confined spaces, and even responding to hydrogen balloon bursts. These field tests were supported by wireless data logging using Bluetooth-enabled electronics, and the sensor’s performance was benchmarked against commercial hydrogen detectors.
Key Findings
The sensor delivered exceptional results. It achieved a response factor greater than 10,000, a sub-second response time, and a detection limit as low as 192 parts per billion. These figures surpass many existing sensors, particularly in terms of speed and sensitivity.
At the core of its performance is the de-doping mechanism—hydrogen molecules interact with the p-doped state induced by oxygen, leading to a measurable and reversible decrease in current. This reversible process enables the sensor to support real-time monitoring without performance degradation.
Long-term tests confirmed the sensor’s stability over nearly two years of ambient storage. Even after extended exposure to real-world conditions, it maintained consistent responsivity and accuracy. Field demonstrations further reinforced its capabilities: in every scenario, the sensor quickly and reliably detected hydrogen, outperforming commercial counterparts—especially in terms of power efficiency and response time.
One standout advantage is the sensor’s ultra-low power requirement of less than 2 μW, which eliminates the need for additional heating elements typically found in other resistive sensor systems.
The team also focused on manufacturing scalability. Sensors produced using screen-printing performed comparably to those made with spin-coating, confirming the technology’s readiness for large-scale production. This scalability positions the sensor as a strong candidate for widespread deployment, particularly in distributed networks for early hydrogen leak detection in infrastructure, vehicles, or industrial sites.
Conclusion
This study introduces a highly capable organic hydrogen sensor that addresses longstanding challenges in the field. It offers fast, sensitive, stable, and low-power detection in ambient conditions. Built on a well-understood mechanism involving reversible modulation of charge carrier density, the device delivers practical and reliable performance for real-world applications.
As the demand for safe hydrogen technologies grows, whether in renewable energy, transportation, or industrial safety, innovations like this could enable smarter, more responsive detection systems across a range of sectors.
Journal Reference
Mandal S., Marsh A.V., et al. (2025). A robust organic hydrogen sensor for distributed monitoring applications. Nature Electronics 8, 343–352. DOI: 10.1038/s41928-025-01352-y, https://www.nature.com/articles/s41928-025-01352-y