Guwahati, May 19 – A groundbreaking advancement in environmental safety and forensic investigations has emerged from the Indian Institute of Technology (IIT) Guwahati. A dedicated research team has successfully developed a highly responsive fluorescent sensor capable of detecting cyanide in both water and human cells using only a UV light source, according to an official statement released on Monday.

Cyanide, a dangerously toxic compound, is extensively utilized in various industrial processes, including the manufacturing of synthetic fibers, metal cleaning, plastics, electroplating, and gold mining. Unfortunately, improper disposal of cyanide can lead to its release into the environment, contaminating soil and water sources. The consumption of water tainted with cyanide can severely disrupt oxygen supply in the human body, posing significant health risks, including severe effects or even death from minimal exposure. This alarming scenario underscores the urgent need for effective sensors that can detect trace amounts of cyanide in different materials.

The newly developed fluorescent chemosensor operates on a “turn-on” response mechanism, which is more effective than traditional sensors that exhibit a “turn-off” response. The “turn-on” approach enhances detection clarity and avoids false negatives. The sensor is based on a compound known as 2-(4′-diethylamino-2′-hydroxyphenyl)-1H-imidazo-[4,5-b]pyridine, which initially emits a weak blue fluorescence under UV light. Upon the presence of cyanide, the fluorescence intensifies and shifts to a brighter cyan color due to a chemical transformation in the molecule. This reaction is highly specific to cyanide, particularly within a carefully selected solvent system that includes water.

Prof. G Krishnamoorthy, leading the research team from the Department of Chemistry, highlighted the sensor’s versatility. It demonstrates accuracy levels between 75% and 93% when tested in both laboratory solutions and real-world samples, such as river and tap water. Furthermore, the sensor can be embedded into paper strips for portable testing and has shown effectiveness in live cell imaging, indicating its potential for applications in environmental and forensic investigations.

The research team utilized a combination of laboratory experiments and advanced computational calculations, known as DFT calculations, to validate the sensing mechanism of this innovative technology. Additionally, the molecular sensor has been shown to function similarly to a basic logic gate, a fundamental component in digital electronics, suggesting future applications in smart, sensor-based electronic devices designed for real-time detection of hazardous chemicals like cyanide.

This significant study has been published in ‘Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy’ and was conducted in collaboration with Prof. Bithiah Grace Jaganathan from the Department of Bioscience and Bioengineering at IIT Guwahati. The research was supported by scholars Mongoli Brahma, Arup Das Kanungo, Minati Das, and Sam P Mathew, who contributed to the development of this sensor. Looking ahead, the research group aims to create a simple kit for testing a variety of analytes, further enhancing the potential applications of this innovative technology.