Daijiworld Media Network - New Delhi
New Delhi, Sep 1: Researchers at the Indian Institute of Technology Guwahati have created a groundbreaking sensor using milk protein and thymine to detect harmful mercury and antibiotic contamination in water—contaminants linked to serious health risks like cancer.
With increasing urbanization, industrialization, and pharmaceutical use, water pollution has become a critical threat to ecosystems and human health globally. Addressing this, the IIT Guwahati team designed a nanosensor made from carbon dots—tiny particles just a few billionths of a meter in size—that fluoresce under ultraviolet light. When exposed to contaminants such as mercury or tetracycline antibiotics, the sensor’s glow dims, offering a rapid, visible alert even at very low pollutant levels.
Professor Lal Mohan Kundu from IIT Guwahati’s Chemistry Department explained, “Detecting pollutants like mercury and antibiotics is crucial, not only in water but also in biological fluids. Mercury is highly carcinogenic, and excessive antibiotics can cause serious health problems. Our sensor can identify these at ultra-low concentrations.”
Tetracyclines, commonly prescribed for respiratory infections, often find their way into water bodies through improper disposal, contributing to antibiotic resistance. Mercury exposure, especially in organic form, is linked to cancer, neurological issues, and cardiovascular diseases, underscoring the need for precise and timely detection.
The sensor’s carbon dots were synthesized from affordable, natural materials—milk protein and thymine, a DNA base. This choice leverages their inherent fluorescence and tiny size for exceptional sensitivity. Laboratory tests showed the sensor reacts within 10 seconds, detecting mercury at just 5.3 nanomolar and tetracycline antibiotics at 10?¹³ nanomolar—well below US EPA safety limits.
Versatility was demonstrated through successful trials in diverse samples including tap water, river water, milk, urine, and serum. For practical use, the team also embedded the sensor onto paper strips that reveal contamination under a UV lamp, enabling quick, on-site water testing.
This novel, cost-effective sensor promises not only improved water safety but also potential future applications in biomedical fields, thanks to its biocompatibility. However, researchers stress the need for further validation before commercial deployment.