The device, called ε-µD, relies on screen-printed carbon electrodes embedded in a simple microfluidic chip and uses electrochemical impedance spectroscopy to detect bacterial growth and antibiotic susceptibility. Unlike traditional techniques that require complex fabrication and highly skilled operators, this lab-on-chip is economical and suitable for smaller clinics and rural healthcare centres, according to a statement.
The research, published in Nature Scientific Reports, was led by Prof S Pushpavanam and Dr. Richa Karmakar from IIT Madras, along with research scholars Diksha Mall and Saranya Gopalakrishnan, Director of Kaappon Analytics India Pvt Ltd, a startup incubated at IITM Research Park.
Highlighting its potential impact, Prof. Pushpavanam said, “Our specially prepared nutrient solution not only supports bacterial growth but also enhances the sensitivity of the electrical signals we use for detection. This approach will make a real impact on patients in intensive care units, helping doctors prescribe the right treatment quickly.”
The device was tested on E. coli and B. subtilis using antibiotics with different modes of action — ampicillin and tetracycline. It successfully differentiated between resistant and non-resistant strains within three hours. Further, trials on urine samples spiked with E. coli confirmed its applicability in clinical diagnostics, the statement added.
Karmakar explained that the system measures changes in electrical signals as bacteria grow in the presence of antibiotics. A new metric, Normalized Impedance Signal (NIS), developed by the team, enables clear identification of resistant strains.
With antimicrobial resistance (AMR) identified by the World Health Organization as a top global health threat, the IIT Madras team believes ε-µD could play a crucial role in improving early diagnosis, guiding targeted treatments, and curbing antibiotic misuse, especially in low-resource settings.
The researchers are currently carrying out clinical validation at the IITM Institute Hospital and plan to commercialise the technology through Kaappon Analytics India Pvt Ltd.
