Whatever your views on legalising cannabis, any half-way reasonable person would surely agree that when the stuff endangers others it should be controlled. In other words, as with drink-drivers, drug-drivers should be pushed off the road.

Now a team of Oxford University scientists has come up with a revolutionary kit to enable police to detect in seconds whether or not you have been taking the weed before taking the wheel and soon it will be able to detect traces of amphetamines and 'speed', too.

The kit, brainchild of Prof Richard Compton and Dr Craig Banks of Oxford University's chemistry department, has been taken up by Isis Innovation, the Oxford company which spins out potential money-making ideas from academia to the world of commerce.

Next week the company, named Oxford ElectroChem Sensors, will submit its business plan at the Oxford University Business Plan Competition, the UK's largest competition of its kind, set up as part of Oxford's annual Venturefest the annual summer jamboree designed to bring entrepreneurs and investors together.

Judges at the competition, to be held at the Said Business School on Tuesday, will award £15,000 to the "most fundable" plan. Oxford ElectroChem Sensors is one of just six finalists, out of 117 entrants from around the world, including USA, Sweden, and Singapore.

Typical of the razzmatazz of Venturefest is the format of the business plan presentations: for example new chief executive of Oxford ElectroChem Sensors, serial entrepreneur John Parselle, will have to give a one-minute "elevator pitch" to an audience of entrepreneurs and business angels. Even his spiel will be judged in a manner reminiscent of TV programme Dragons' Den.

Presenter of the best pitch, as defined by democratic vote, will win the £1,000 Audience Prize. Gone, apparently, are the days when a marriage between money and ideas was an almost mystical process, carried on discreetly behind closed doors.

But the way in which this new drug detection idea, now looking for investors, has reached the stage of becoming a candidate for serious money illustrates just how potential high-flyers, invented at Oxford University, leave the nest and their progenitors hope take off.

Prof Compton said: "My group has been working on electrochemical sensors (as well as fundamental electrochemical science) for sometime. For example, in collaboration with petrol pump company Schlumberger, we have patented and developed sensors which work at the bottom of oil wells under conditions of extreme temperature and pressure.

"Over recent years we have developed a synergistic relationship with Terry Pollard and David Baghurst at Isis so that they do not simply take completed projects and then set about commercialising them, but rather also have early input into the identification of suitable projects in our case ideas for specific target chemicals for which we might invent and design electrochemical sensors.

"The drug-testing arose exactly in this way."

At Isis Innovation, project manager Terry Pollard admitted somewhat ruefully that after nursing the company to this stage, handing over the management to Australian entrepreneur John Parselle was a little like parting with his baby. However he reminisced on how Oxford Catalysts, which floated on the London Stock Exchange in April for £15m, also grew as a spin-out from Oxford University and also presented its business plan at Venturefest 2004. Its products aim to make fuels of the future cleaner and leaner. Mr Pollard said: "The business plan is extremely useful. It forces you to write everything down and think about it."

Oxford ElectroChem Sensors produced a working prototype model to demonstrate its efficiency. To fund this, Isis called on the Universities Proof of Concept Fund for £25,000. The fund is itself a joint project of Oxford and Cambridge universities, University College London, and Imperial College.

Mr Parselle met Mr Pollard through the IP Group, the merchant bank which has funded many of Oxford University's activities, including giving £20m towards the new £60m chemistry research laboratory opened by the Queen in 2004.

Prof Compton explained how chemistry spin-outs from Oxford work out these days. He said: "In return for an upfront sum, the bank receives half of the university equity in chemistry spin-outs for 15 years.

"The typical equity split in spin-outs is: founders 30 per cent; management 20 per cent; the University 25 per cent; and the academics 25 per cent.

"Once the company is created, the interests of the bank and the university are identical, but the department also benefits from help from IP Group in preparing business plans and raising funding."

In the 1980s Mr Parselle, 58, pioneered the introduction at airports of automatic revolving security doors. In the 1990s he brought Fingerscan to market in Silicon Valley, California. It is the device that can immediately recognise, say, a laptop computer user the minute he or she touches the mouse pad.

He said: "In Australia there is definitely a demand for a roadside drug-testing kit. Lorry drivers on long-distance journeys may be tempted to operate on speed or on amphetamines."

But why is this new invention different to other models on the market, notably those produced by rival Oxfordshire company Cozart? Back to Prof Compton: "Our approach is chemical, not biological. I believe this is a major strength.

"The components are reliable and robust and lend themselves to the construction of simple test strips much as used by diabetics for roadside testing."

Oxford ElectroChem Sensors faces tough competitors in the business plan competition. They include a painless diabetic diagnosis system, a system that can more easily ensure that surrounding body tissue accepts transplants, a coating which makes it more difficult for patients to contract blood infections from medical instruments, and a nanobiotechnology service to speed drug discovery research.