A disposable drugs test, developed by Brit boffins, allows parents to check whether their wards have been taking cannabis or cocaine by analysing a droplet of their saliva.
The handheld device, which resembles a pregnancy testing kit, costs just 1.50 pound and produces an accurate result within five minutes.
Its creators say it could be available within two years.
The Vantix sensor was developed to help police carry out speedy roadside drug-driving tests, but it could just as easily be used by parents who are worried their children are taking drugs.
Kevin Auton of Universal Sensors has admitted that the test would be controversial and could have 'huge implications for society'.
'In America, parents are taking samples of their children's saliva and hair and sending them off to labs to see if their children are taking drugs. If there is demand for it here, it would be an interesting market," the Daily Mail quoted him as saying.
"It is controversial but the test can be used in the home for worried parents to test if their children are taking drugs.
"We are very focused on getting the test out of the laboratory and on to other platforms. It is as simple to use as a pregnancy test," he added.
The sensor works by using a disposable 5mm wide chip printed on a piece of plastic.
On the surface of the chip are antibodies that respond to particular chemicals in drugs - such as the THC molecule found in cannabis.
If an antibody on the chip comes into contact with its 'target' chemical, a tiny electrical current flows in the chip. The current is amplified by a larger, handheld device, which lights up a warning lamp.
The chip can be adapted to detect a range of chemicals - including those only found in drugs or explosives.