LONDON, July 23: When Tony Turner started studying the arcane area of biosensors 30 years ago, the market for those devices was worth only 5 million dollar a year and he used to see one research paper on the subject every two years. Now a professor at Linkoping University in Sweden running a department dedicated to bioelectronics, Turner says a study he led at Cranfield University in Britain found the devices now generate annual sales of 13 billion dollar and spawned 6,000 research papers last year. (agencies)