New Delhi: Scientists developed a nicotine detection sensor that glows upon exposure, enabling rapid and low-cost identification of nicotine and its metabolite cotinine in living cells and aqueous media.
Researchers from the Institute of Nano Science and Technology (INST), Mohali, an autonomous body under the Department of Science and Technology, created the sensor using iron-based metal-organic framework nanospheres. The team designed these microscopic structures to detect nicotine and cotinine quickly and efficiently.
Nicotine remains a highly addictive substance, while cotinine serves as a stable biomarker found in blood, saliva, and urine. Therefore, early detection of these compounds is critical for monitoring smoking and second-hand smoke exposure. Existing methods such as GC-MS, HPLC, electrophoresis, and immunoassays are costly, time-consuming, and require complex preparation.
The scientists synthesised the nanospheres using a solvothermal process and tested them for safety and performance. These sponge-like structures contain tiny pores that trap nicotine molecules, making detection easier.
Nicotine detection sensor shows fluorescence shift in testing
Using intracellular imaging and confocal microscopy, the researchers observed that the nicotine detection sensor emitted a brighter glow when nicotine or cotinine entered the pores. The fluorescence also shifted towards blue, confirming successful detection inside living cells.
The study, published in the journal Nanoscale, found the sensor to be selective and recyclable. Researchers said the fluorescence enhancement occurred due to host–guest interactions and electron transfer, which strengthened the emission signal. The system worked effectively in aqueous environments and required simple operation.
The team highlighted that iron-based frameworks offer a safe and abundant material option with low cytotoxicity and high biocompatibility. As a result, the nicotine detection sensor could support non-invasive health monitoring and research on smoking, addiction, and metabolism.
Scientists added that the technology could lead to low-cost screening kits for tobacco exposure and expand into fluorescence-based biosensing platforms for other biomarkers in the future.
