A POCKET-SIZED detector that can instantly spot traces of illicit drugs could
be on the way. It would make life tougher for drug dealers by letting police
confirm immediately which drugs, if any, a person has handled.
At the moment, drugs and forensic evidence from drug busts have to be sent to
approved labs for analysis if the results are to stand up in court. For rough,
on-site testing, police use sniffer dogs and 鈥渋on scans鈥�. Ion scanners are
around the size of a small fridge, says Chris Lennard from the Australian
Federal Police forensic laboratory in Canberra. Drug samples are put in a cell
in the ion scanner and vaporised. The time it takes for the particles to drift
from one end of a cell to the other identifies the drug, he says.
Simon Lewis and colleagues at Deakin University in Geelong near Melbourne set
out to create a pocket-sized drug detector for people with no lab training.
鈥淪uppose I鈥檝e got an empty bag here and I want to know, did it ever contain
drugs?鈥� says Lewis. You just take a swab from the bag and mix it with deionised
water in a vial. You then fill a second vial with a solution of a metal complex
that varies according to the drug you suspect might be there.
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The two vials are slotted into holes in Lewis鈥檚 detector where the liquids
from each vial are mixed in precise quantities. As they mix, a reaction between
the drug and metal complex produces a brief flash of light. A light sensor
identifies the drug by measuring the intensity, wavelength and duration of the
flash, says Deakin.
In a test, Lewis used a compound called ruthenium metal complex to look for
the common analgesic drug codeine. He found he could detect 6 micrograms of the
drug in a litre. 鈥淚t鈥檚 like being able to taste a crushed Tic Tac in an
Olympic-sized swimming pool,鈥� he says.
By choosing specific metal complexes that react with different drugs to
produce light, the system could quickly distinguish between hard drugs like
cocaine and more innocuous substances, says Lewis.
Zoran Skopec, director of the Australian Forensic Drug Laboratory in Sydney,
is interested in Lewis鈥檚 device but wonders how well it would fare if there was
a mixture of drugs. 鈥淔ield kits like this might work with well-established
chemicals,鈥� he says. 鈥淏ut new drugs or particular mixes often give a number of
confusing answers.鈥�
Lewis agrees that mixtures can be difficult to identify. 鈥淭hat鈥檚 what we鈥檙e
working towards,鈥� he says.