A breakthrough in gas sensor technology could significantly enhance accuracy and reliability in air quality monitoring and industrial safety. Researchers have introduced a novel ratiometric-gas sensing technique that leverages an organic-inorganic hybrid covalent superlattice material called AgBDT (1,4-benzenedithiol). Published in Nature Communications, the study highlights how this method compensates for temperature-induced baseline drift, addressing a key challenge in gas detection.
Study: Organic-inorganic hybrid covalent superlattice for temperature-compensated ratiometric gas sensing. Image Credit: PVRM/Shutterstock.com
Background
Gas sensors play a crucial role in monitoring air quality, ensuring industrial safety, and supporting medical diagnostics. However, their accuracy is often compromised by temperature fluctuations, which can lead to unreliable readings.
Traditional chemiresistive sensors operate by detecting resistance changes when exposed to target gases. While these sensors are valued for their simplicity and low power consumption, they frequently suffer from baseline drift due to temperature variations. Existing solutions, such as temperature compensation mechanisms or complex algorithms, tend to increase cost and system complexity.
Recognizing these challenges, the researchers behind this study proposed a ratiometric approach to gas sensing. Their method utilizes AgBDT, a material with dual responsiveness to light and gases, to create a self-referenced measurement system that inherently compensates for temperature variations.
The Study
For the study, the researchers synthesized AgBDT using a hydrothermal method, producing nanosheets with a well-defined multi-quantum well structure. Characterization revealed its strong photoelectric response, high on/off ratio, and dense active sites, which enhance its gas detection capabilities. The key innovation lies in using the material’s internal photoelectric response as a reference against its gas-sensitive response. This approach enables precise measurement of gas-induced resistance changes independent of temperature fluctuations.
To test the sensor’s performance, the team exposed it to nitrogen dioxide (NO2) at varying concentrations and temperatures ranging from 25 °C to 65 °C. By analyzing the ratio of gas-sensitive and photoelectric responses, they assessed its stability and accuracy under different conditions.
Results and Discussion
The AgBDT-based sensor demonstrated remarkable sensitivity, detecting NO2 at concentrations as low as 3.06 ppb. More importantly, the ratiometric approach significantly improved reliability, reducing the coefficient of variation (CV) from 21.81 % to 7.81 %—a substantial enhancement compared to traditional chemiresistive sensors, which exhibited considerable output fluctuations.
The researchers attribute this improvement to AgBDT’s unique structural properties, which facilitate both gas detection and light absorption. This dual functionality ensures stable and accurate readings even under varying environmental conditions. The study’s findings underscore the potential for practical gas sensors capable of maintaining performance without the need for additional temperature compensation technologies.
Beyond its high sensitivity and stability, the AgBDT-based sensor design offers a streamlined alternative to conventional compensation methods, simplifying implementation while maintaining effectiveness. The results set a foundation for further research, potentially extending this ratiometric approach to other materials and applications.
Conclusion
This study presents a promising advancement in gas sensor technology by addressing a long-standing challenge—temperature-induced instability. By integrating a ratiometric-gas sensing approach with AgBDT, the researchers have developed a method that significantly enhances sensor accuracy and reliability. The marked reduction in measurement variability highlights its potential for real-world applications in air quality monitoring, industrial safety, and medical diagnostics.
The findings not only represent a major step forward in gas sensing but also open new avenues for refining sensor technologies. By combining high sensitivity with built-in temperature compensation, this approach sets a new benchmark for gas detection, paving the way for more reliable and practical sensor solutions in the future.
Journal Reference
Li KF., Yu CH., et al. (2025). Organic-inorganic hybrid covalent superlattice for temperature-compensated ratiometric gas sensing. Nature Communications 16, 1560. DOI: 10.1038/s41467-025-56609-z, https://www.nature.com/articles/s41467-025-56609-z