Indian Scientists Develop Fluorescent Nano-Sensor for Rapid Detection of Nicotine Exposure and Smoking Biomarkers

Nicotine, the addictive component in tobacco, and cotinine, its long-lasting biomarker found in blood, saliva, and urine, are critical indicators used in assessing smoking and second-hand smoke exposure.

In a breakthrough that could transform public health monitoring and addiction research, scientists at the Institute of Nano Science and Technology (INST), Mohali have developed a cutting-edge fluorescent nano-sensor capable of rapidly detecting nicotine and its key metabolite, cotinine, in water-based environments and living cells.

The innovation offers a faster, cost-effective, and highly sensitive alternative to conventional detection methods, paving the way for early identification of tobacco exposure and improved monitoring of smoking-related health risks.

A Game-Changer for Tobacco Exposure Detection

Nicotine, the addictive component in tobacco, and cotinine, its long-lasting biomarker found in blood, saliva, and urine, are critical indicators used in assessing smoking and second-hand smoke exposure. However, existing detection techniques such as gas chromatography-mass spectrometry (GC-MS), high-performance liquid chromatography (HPLC), and immunoassays are often expensive, time-intensive, and require specialised expertise.

The newly developed sensor addresses these limitations by offering a simple, rapid, and biocompatible solution that works effectively in aqueous environments and biological systems.

How the Nano-Sensor Works

At the heart of the innovation is an iron-based metal-organic framework (Fe-III-MOF) nanosphere—a microscopic, porous structure that acts like a molecular sponge.

These nanospheres are synthesized using a solvothermal process, creating a highly porous material capable of trapping nicotine and cotinine molecules. Once these molecules enter the pores, the sensor exhibits a unique “turn-on” fluorescence effect—glowing brighter with a noticeable blue shift.

Using advanced imaging techniques such as intracellular imaging and confocal microscopy, researchers observed how the nanospheres interact within living cells, confirming their effectiveness in real-time detection.

High Sensitivity, Selectivity, and Reusability

Published in the journal Nanoscale, the study highlights several key advantages of the sensor:

• High selectivity for nicotine and cotinine over other molecules

• Fluorescence enhancement driven by host–guest interactions and electron transfer

• Recyclability, enabling repeated usage

• Low cytotoxicity and high biocompatibility, making it safe for biological applications

These features make the sensor particularly suitable for both laboratory research and potential clinical or field applications.

Affordable and Scalable Innovation

One of the most promising aspects of this development is the use of iron—a widely available and cost-effective material—making the technology economically viable for large-scale deployment.

The simplicity of operation, combined with its ability to function in water-based systems, opens the door for portable, low-cost diagnostic kits that could be used in hospitals, research labs, and even community health settings.

Implications for Public Health and Research

The sensor holds significant potential across multiple domains:

• Public health screening: Rapid identification of tobacco exposure, including second-hand smoke

• Addiction monitoring: Tracking nicotine metabolism and cessation progress

• Medical research: Studying the biological impact of nicotine at the cellular level

• Future biosensing platforms: Adaptation for detecting other biomarkers using similar MOF-based systems

By enabling early and accurate detection of nicotine exposure, the technology could support more effective interventions and policy measures aimed at reducing tobacco-related harm.

Towards Next-Generation Biosensing Technologies

This innovation represents a broader shift toward nanotechnology-driven biosensing, where smart materials are used to detect biological molecules with high precision and speed.

As researchers continue to refine the technology, it could evolve into a versatile platform for detecting a wide range of disease markers—ushering in a new era of non-invasive, real-time health monitoring.