August 2015

First field demonstration of standoff detection of buried landmines using bacterial biosensors

Standoff detection of buried landmines by fluorescent bacterial biosensors (FBB) was demonstrated for the first time in a field experiment. This standoff detection scheme enables direct access to the sampled area without endangering the operating personnel and the equipment. 
The technique is based on bacteria that were genetically engineered to emit molecules of green fluorescent protein in response to the presence of TNT and its derivative DNT. A brief overview of the technique can be found in [REF13]. A testing area was prepared with layers of TNT and DNT flakes and antipersonnel landmines buried in specific locations under 2 cm of different types of soil. The targets were buried a few weeks before the experiment. 24 hours before the measurements the area was covered with beads containing the bacteria. The area was then scanned from a distance of 25 meters by a special purpose apparatus for fluorescent measurements employing a phase locking detection scheme. It was observed that locations under which the targets were buried emitted strong fluorescent signal, whereas control areas that did not contain any targets emitted weak signals. As such, the field demonstration provides a proof of concept for FBB based standoff detection scheme and validates its viability.
The experiment was conducted by a team of the OECL headed by Prof. Agranat, in collaboration with the group of Prof. Shimshon Belkin of the Institute of Life Sciences that developed the bacteria, and the group of Prof. Amos Nussinovich of the faculty of Agriculture that developed the packaging beads.