Researchers at the Indian Institute of Technology (IIT) Guwahati have developed a fluorescent sensor capable of detecting cyanide in both water and human cells using only a UV light source. This innovation offers a rapid, cost-effective, and highly sensitive method for identifying the presence of this toxic compound in various environments.
Key Features of the Fluorescent Sensor
- “Turn-On” Fluorescence Mechanism: Unlike many existing sensors that diminish in brightness upon detecting a target substance, this sensor increases its fluorescence intensity when cyanide is present. This “turn-on” approach reduces the risk of false negatives and enhances detection clarity.
- High Sensitivity: The sensor can detect cyanide concentrations as low as 0.2 μM in aqueous samples, significantly below the World Health Organization’s permissible limit of 1.9 μM in drinking water.
- Versatility: Effective in various real-world samples, including river water, tap water, and even within live biological cells. It can also be integrated into paper strips for portable testing applications.
- Digital Logic Gate Functionality: The sensor exhibits properties akin to basic logic gates, suggesting potential applications in developing smart, sensor-based electronic devices for real-time chemical detection.
Scientific Basis and Development
The sensor is based on the compound 2-(4′-diethylamino-2′-hydroxyphenyl)-1H-imidazo-[4,5-b]pyridine. Under UV light, this compound exhibits weak blue fluorescence, which intensifies and shifts to a bright cyan color upon interaction with cyanide ions. This specific chemical reaction forms the basis of the sensor’s detection capability.
The research team, led by Professor G. Krishnamoorthy from the Department of Chemistry, conducted a combination of laboratory experiments and advanced computational calculations (Density Functional Theory) to confirm the sensing mechanism. The study was published in Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy and involved collaboration with Professor Bithiah Grace Jaganathan from the Department of Bioscience and Bioengineering.
Implications and Future Developments
Cyanide is a highly toxic compound used in various industrial processes, including synthetic fiber production, metal cleaning, plastics manufacturing, electroplating, and gold mining. Improper disposal can lead to environmental contamination, posing serious health risks.
The development of this sensor provides a valuable tool for environmental monitoring, medical diagnostics, and forensic investigations. Its ability to function in diverse settings and its compatibility with portable testing formats make it a promising solution for rapid and reliable cyanide detection.
The research team is currently working on developing a simple test kit capable of detecting a broader range of toxic compounds, aiming to make high-precision chemical testing more accessible and widely deployable.
