Scientists from Institute of Nano Science and Technology (INST), Mohali an autonomous institute under Department of Science and Technology (DST) have developed a tiny fluorescent “turn-on” sensor capable of rapidly detecting nicotine and its major metabolite, cotinine, in aqueous media and living cells. The research has been published in the journal Nanoscale.
Why Does It Matter?
Smoking and second-hand smoke remain major global health concerns. While nicotine is highly addictive and harmful, cotinine– its stable metabolic byproduct serves as a reliable biomarker found in blood, saliva, and urine, indicating long-term nicotine exposure.
Conventional detection methods such as GC-MS, HPLC, electrophoresis, and immunoassays are expensive, time-consuming, require skilled operators, and involve complex sample preparation — making them impractical for rapid screening.
New Technology: Fe-III-MOF Nanosphere
The sensor is built on an iron metal-organic framework (Fe-III-MOF) nanosphere — a microscopic, sponge-like structure made from iron, synthesised through a solvothermal process. The structure is full of tiny pores that trap molecules like nicotine and cotinine.
When nicotine or cotinine enters the pores, the nanosphere begins to glow brighter with a shift towards blue– a “turn-on” fluorescence response. Scientists confirmed this using intracellular imaging and confocal microscopy to track cellular uptake. The fluorescence enhancement occurs due to host-guest interactions and electron transfer, leading to a stronger emission signal.
Key Features of the Sensor
- Highly selective: specifically detects nicotine and cotinine
- Recyclable: can be reused
- Biocompatible: low cytotoxicity, safe for biological applications
- Works in aqueous medium: suitable for real biological samples
- Simple to operate: no complex equipment needed
- Iron-based MOFs are abundant and cost-effective
Potential Applications
- Public health monitoring and smoking biomarker screening
- Non-invasive health monitoring and medical research on smoking, addiction, and metabolism
- Development of low-cost rapid screening kits for tobacco exposure
- Fluorescent MOF-based biosensing platforms for other biomarkers
- Cellular and biological research related to nicotine metabolism