IIT-G team’s new low-cost device to detect bacteria

Detection of bacteria infection is set to be as handy and quick as blood sugar and pregnancy detection.

A team of researchers from Indian Institute of Technology Guwahati (IITG) has developed a low cost and handheld device, which can detect bacteria quickly. The research team led by Prof. Parameswar K. Iyer of the department of chemistry, and Prof. Siddhartha S. Ghosh of the Department of Biosciences and Bioengineering said rapid detection of bacteria will not only be helpful in healthcare but also in anti-bioterrorism and environmental monitoring applications.

The novel, low-cost, bio-compatible sensor can detect bacteria almost instantaneously without the need for cell culture and microbiological assays, said a statement issued by the team. At present, the detection of bacteria in body fluids is done in laboratories.

"Bacterial infection is a common cause of morbidity and mortality worldwide and despite development of a range of antibiotics, the challenge continues to lie in detecting and diagnosing bacterial infection early on, as present detection techniques tend to be time-consuming," it said.

Their work has been patented and published in the July 2019 issue of the reputed peer-reviewed Journal of Materials Chemistry A of the Royal Society of Chemistry, said the statement. The team also comprised Anamika Dey, Ashish Singh, and Deepanjalee Dutta, the three former PhD scholars from Center for Nanotechnology, IITG.

Professor Iyer said, "The current diagnosis process are frustratingly time consuming, especially when time is of the essence in administering treatment. The newly developed device can detect bacteria faster than conventional assay-based methods, which are restricted by the need for expensive apparatuses and trained personnel.  What would be useful are hand-held rapid detection kits like those used for blood sugar monitoring and pregnancy detection.”

The team developed and used an Organic Field Effect Transistor (OFET) to detect this surface charge. The OFET is an electronic device that works on the principle that charges in the vicinity of the channels of certain semiconductors can induce a current in them. Thus, the charges on the surface of the bacterium, induces a current in the OFET, which is registered and read. 

The OFET devices developed by the team consists of a unique and hybrid tri-layer dielectric system built on simple glass and flexible PET (a kind of plastic) substrates and can operate at ultra-low operating voltages. The team has shown that this OFET sensor can not only detect bacteria, but also differentiate between Gram positive and Gram negative bacteria, said the statement.