BITS Pilani, Partner Labs Build Portable IoT Device to Detect High Explosive TKX-50

Researchers from BITS Pilani, Hyderabad and Goa campuses, IISER Kolkata and

other institutions have developed a portable device that can detect very

small amounts of TKX-50, a high-energy explosive material.

The device is still at the laboratory testing stage and uses a specially

made polymer that lights up when it comes into contact with TKX-50. It

converts that response into an electronic reading which can be sent

wirelessly.

The study, ‘Molecular-To-Device Integration: A Turn-On Polymeric Receptor

for IoT-Enabled Detection of Explosive TKX-50’, was published in Advanced

Materials Technologies. Researchers from the Defence Materials and Stores

Research and Development Establishment in Kanpur and CSIR-Central Salt and

Marine Chemicals Research Institute in Bhavnagar also worked on the project.

The polymer normally gives off very little light. When TKX-50 comes into

contact with it, its glow increases by about 120 times under laboratory

conditions. The change is also visible under ultraviolet light.

Scientists tested whether seven other explosives would cause a similar

reaction. These included RDX, TNT, HMX, CL-20, FOX-7, TATB and PETN. The

large increase in light was reported only when TKX-50 was added. Tests with

common salts and ammonium compounds also did not produce the same response.

Laboratory measurements showed that the polymer could detect TKX-50 at

concentrations as low as 29.2 nanomolar. The complete portable device had a

detection limit of 930 nanomolar.

A light detector inside the unit converts the glow into an electrical

reading. The device also contains an LED, a microcontroller and a small

display. It can send readings to the ThingSpeak platform at 20-second

intervals, while a 3D-printed casing helps reduce interference from

surrounding light. “We have translated that recognition event into an

electrical signal that can be measured, processed and transmitted using a

compact IoT-enabled platform,” said Prof Sanket Goel of BITS Pilani.

The device has so far been tested using TKX-50 mixed into a laboratory

solution. It has not been tested in real-life samples such as luggage, air,

soil or surfaces. Researchers describe it as a proof of concept, and further

testing under real-world conditions will be needed before it can be used

outside the laboratory.