Researchers at the Indian Institute of Technology (IIT) Bhubaneswar have developed an innovative technology that can rapidly identify arsenic contamination in water sources without the need for laboratory infrastructure, helping ensure arsenic-free drinking water.
The presence of arsenic in water is extremely dangerous as it is a highly toxic, tasteless and odourless metalloid that causes arsenicosis, a chronic and debilitating condition that can lead to severe internal diseases and fatal cancers.
The Sensors and Spectroscopy Research Group of the School of Electrical and Computer Sciences (SECS) at IIT Bhubaneswar has developed an affordable, highly sensitive and field-deployable technology to detect arsenic contamination, a major public health challenge affecting millions of people in India and several other countries.
As part of efforts to translate laboratory research into practical solutions, the researchers have manufactured a compact handheld arsenic detection device, “ArsenSafe”, with the help of Nano Semic Pvt Ltd, a startup incubated at the Research and Entrepreneurship Park of IIT Bhubaneswar. The startup is led by Sayan Dey and Akshay K, both faculty members of the institute.
Designed for rapid, cost-effective and on-site water quality assessment, ArsenSafe eliminates the need for sophisticated laboratory facilities and chemical-based testing procedures. The portable device enables accurate detection of arsenic contamination in drinking water, making water testing faster, simpler and more accessible for a wide range of users.
The technology employs a reduced graphene oxide (rGO)-based sensing platform and has been developed for easy operation with minimal training and setup requirements.
Dey said the device can be deployed by government agencies, public health departments, environmental monitoring organisations, water treatment companies, industries, non-governmental organisations and even individual consumers seeking to assess the safety of drinking water sources.
“The prototype has already achieved a high Technology Readiness Level (TRL) and has undergone successful testing using water samples collected from the IIT Bhubaneswar campus and surrounding areas,” he said.
The development complements the team’s research in nanotechnology-enabled sensing systems.
In a recent study published in the journal Environmental Science: Nano of the Royal Society of Chemistry (RSC), the research team comprising Arijit Pattra, Bathula Sathwik and Himanshu P Padole, along with Dey, reported the development of an advanced microsensor based on reduced graphene oxide and its derivatives for detecting extremely low concentrations of arsenic in drinking water.
The sensor has demonstrated the capability to identify arsenic levels that comply with the safety standards recommended by the World Health Organisation (WHO).
“It is a convergence of nanotechnology and machine-learning techniques to enhance the sensitivity, reliability and efficiency of water quality monitoring systems,” said Pattra, one of the researchers.
According to IIT officials, the research has received international recognition, with the editorial board of Environmental Science: Nano inviting the article to be featured in its special themed collection on “Nanosensing”. The selection underscores the scientific importance and potential real-world impact of the technology, they said.
Arsenic contamination remains one of the most serious water-quality concerns globally, particularly in regions dependent on groundwater sources. Long-term exposure to arsenic-contaminated water can lead to severe health problems, including cancers, cardiovascular diseases and neurological disorders.
“Technologies such as ArsenSafe could play a crucial role in early detection and prevention efforts, especially in rural and resource-constrained areas where laboratory testing facilities are often unavailable,” Dey added.
Continuous monitoring of arsenic contamination in drinking water is crucial because inorganic arsenic, As(III), poses serious risks to human health.
Existing graphene-based sensors used for detecting heavy metals in water generally use silicon dioxide (SiO₂) or hafnium dioxide (HfO₂) as dielectric materials, while graphene or reduced graphene oxide (rGO) serves as the sensing layer.
Researchers at IIT Bhubaneswar have developed a novel liquid-gated reduced graphene oxide field-effect transistor (rGO-FET) sensor that uses semiconducting rGO along with a graphene oxide (GO) dielectric layer. The device can selectively detect extremely low concentrations of arsenic in drinking water.
The sensor demonstrated outstanding performance, registering a maximum response of 500 per cent when exposed to 40 parts per million (ppm) of arsenic. It also showed rapid detection and recovery capabilities, with response and recovery times of just 17.4 seconds and 11.76 seconds, respectively.
One of the most significant achievements of the study is the sensor’s ability to detect arsenic at concentrations far below prescribed drinking-water safety limits. The device recorded a limit of detection of just 0.720 parts per billion (ppb) and a limit of quantification of 2.40 ppb at room temperature, making it highly sensitive to trace amounts of arsenic.
The sensor also exhibited excellent selectivity, accurately identifying arsenic even in the presence of other metal ions found in water. It remained reusable for up to 70 days while maintaining an accuracy of 98.4 per cent, with only a 2.2 per cent variation in performance over time.
The researchers also addressed interference from nickel (Ni II) ions by using a linear regression-based machine-learning algorithm to improve arsenic measurement in real-world conditions where multiple contaminants may be present. The model achieved a high correlation score (R²) of 0.9732, enhancing the sensor’s quantification capability in mixed-ion environments.
An adsorption-based model developed by the team to explain how the sensor detects arsenic and how the device functions delivered promising outcomes.
When tested on actual tap water and packaged drinking water samples, the sensor, combined with the optimised algorithm, delivered an accuracy of nearly 98 per cent.
The researchers said the newly developed rGO-FET sensor outperformed conventional reduced graphene oxide-based arsenic sensors in terms of sensitivity, selectivity, speed and long-term stability. The technology has the potential to provide a reliable and cost-effective solution for real-time monitoring of arsenic contamination in drinking water.
