More than half a million people have been killed and maimed by anti-personnel mines and these weapons kill or injure between thousands of people a year. More than 300,000 children have been left severely disabled because of landmines. It is estimated that around 110 million anti-personnel mines are in the ground and another 100 million are stockpiled around the world, according to Unicef, quoting the International Campaign to Ban Landmines.
Researchers have harnessed the fluorescence of engineered E.coli bacteria to help detect buried landmines (Sybille Yates/123rf)
The need for safe and effectual landmine detection system is urgent and widespread. Researchers at the Hebrew University in Jerusalem say they have created a remote detection system using lasers and fluorescent bacteria, which could be a possible solution to this long time global problem.
Finding the location of buried landmines remains a treacherous task. Current technology has remained unaltered for 75 years, since around World War II. These methods require teams to physically enter the minefields, and thus risk losing their own life and limbs in the process of saving others. Despite the development of other detection methods, including specially trained rats and other animals, the dated technology means a limited ability to detect non-metal explosives and a large number of false positive identifications.
Landmines are still a scourge in more than 70 countries around the world, killing and injuring thousands.Half the people who stand on an anti-personnel mine die from theirinjuries before they are found or taken to hospital. An even higher percentage of children die because, being smaller, their vital organs are closer to the blast (photo: Pavel Bernshtam/123rf)
Landmines leak explosive vapours that accumulate in the soil surrounding the buried explosives. The researchers found that if engineered E.coli bacteria are sprayed onto these bacteria and allowed to set for a few hours, the location of landmines can be pinpointed by localized areas of fluorescence that are revealed by a laser. The genetically engineered bacteria respond to the residue that comes from the landmines, which most likely contains TNT, and its lesser known degradation product , DNT, which is more volatile and considered an excellent signature chemical for TNT explosives.
Remote detection of buried landmines is a possible application of system to remotely detect buried landmines using a bacterial sensor and a laser-based scanning system (Hebrew University, Israel)
If engineered E. coli bacteria are sprayed onto the bacteria and allowed to set for a few hours, the location of landmines can be pinpointed by localised areas of fluorescence revealed by a laser. The bacterial sensor strain has a reporter where TNT/DNT fuses with the green fluorescent protein gene, which is exposed by a laser-based scanning system. This signal can be recorded and quantified from a remote location.
Some potential issues with the prototype need to be addressed. "Our field data show that engineered biosensors may be useful in a landmine detection system. For this to be possible, several challenges need to be overcome, such as enhancing the sensitivity and stability of the sensor bacteria, improving scanning speeds to cover large areas, and making the scanning apparatus more compact so it can be used on board a light unmanned aircraft or drone," said Professor Shimshon Belkin, from the Hebrew University's Alexander Silberman Institute of Life Sciences, who was responsible for genetically engineering the bacterial sensors.
There are clear and necessary adjustments to make to this advanced detection system, but it is important to invest the time and resources to make it as useful as possible, to benefit more than 70 countries around the world that where landmines are still buried.