Image created by Dr. Michael J. Miller
Researchers at the Indian Institute of Technology (IIT) Guwahati have introduced an innovative method to detect the SARS-CoV-2 virus using clay particles in salt water. The technique relies on observing how the presence of the virus alters the natural settling rate of clay in a saline solution — providing a new low-cost and scalable way to detect infections.
How Clay Reveals the Virus
The research team, led by Prof. T.V. Bharat from the Department of Civil Engineering, discovered that the inter-particle forces in clay change significantly when viral material is present. This variation causes the clay to settle faster or slower depending on the viral interaction, effectively turning the sedimentation behavior into a diagnostic signal.
The study used Bentonite clay, known for its unique chemical structure and strong binding properties. Earlier research had already shown that clay can attach to viruses and bacteriophages. IIT Guwahati’s team took this insight further by proving that the clay-electrolyte system behaves differently when exposed to coronavirus surrogates like the Infectious Bronchitis Virus (IBV).
Simpler Than PCR, More Reliable Than Antigen Tests
Unlike current testing methods — such as PCR, which is accurate but time-consuming and equipment-heavy, or antigen tests, which lack reliability — this clay-based test could offer faster results without complex machinery. “It is as simple as watching sand settle in water,” explained Prof. Bharat, highlighting its potential to revolutionize point-of-care diagnostics.
Perfect for Resource-Limited Settings
This method could be a game-changer for rural and under-resourced regions. Most existing virus detection techniques depend on advanced lab infrastructure and trained technicians — resources not easily available during a health emergency or in remote locations. The new technique, being low-tech and easy to use, fills this critical gap.
Potential for Broader Impact
Beyond COVID-19, this discovery could pave the way for affordable viral detection systems for other infectious diseases. It also holds promise for improving large-scale disease surveillance, especially during pandemics when rapid testing is crucial.