Dogs have had their day

A device capable of detecting tiny quantities of heroin and cocaine on clothing or boxes could become a powerful weapon in the fight against drug smuggling.

The system, developed by Swedish firm Biosensor Applications, can identify quantities of drugs such as cocaine, ecstasy, heroin and amphetamines weighing less than one trillionth of a gram.

Consisting of a handheld sampler and a small analysis system, the device identifies drugs in the same way as the human body by using antibodies that bind to the harmful antigens, said Per Mansson, head of chemistry at Biosensor Applications.

The antibodies are placed on the surface of a tiny quartz crystal, and when an antigen comes along in the form of a trace of heroin or cocaine, the antibody moves off the surface to bind with the drug.

Sensors scan the crystal and report any loss of antibody to the detection system. As different drugs react with different antibodies, the police or customs officials can quickly identify the particular drug.

‘The system can find drugs in containers, cars, on people and in their baggage. It can also help clinics to test people by analysing their urine and saliva,’ said Mansson.The Biosens-D device, which can be used on surfaces such as clothing and paper, takes less than two minutes to analyse a sample, he said. ‘If you tried to hide cocaine in your clothing a container or bag you would always contaminate your hands or hair. Even tiny particles are enough for us to pick up on.’

The potential market for drug-detection equipment is huge, with governments fighting to prevent narcotics entering countries at ports, airports and across land borders, while the drugs culture in prisons has become a serious problem.

Police and customs officials around the world already spend over $250m (£155m) in the area each year, but more than half of this is spent on sniffer dogs. Existing screening technologies, many of them X-ray based, are only capable of detecting bulk quantities of the substances, and often give false alarms.

‘Our system is very selective, so there are few false alarms, and it has a very low detection limit, around the pico-gram level,’ said Mansson.

Biosensor Applications is collaborating with various customs authorities to test the drug-detecting device, and was recently asked to take part in a US trial. ‘We and a number of other companies were invited by US customs to test for cocaine in containers planted with the drug. Not all of the companies were able to detect anything in each of the containers, but we found it all,’ said Mansson.

The technique was originally developed to detect traces of TNT, and the company is also developing sensor devices to identify other forms of explosives. It is also working on an EU project to locate landmines in the Balkans and southern Africa.