Fiber sensor detects anthrax

17 Jun 2002

Technology for a fiber-optic sensor that can detect infectious diseases has been acquired by UK firm BTG.

BTG of the UK, a technology commercialization company, has acquired a diagnostic technology for the real-time detection of infectious diseases, such as anthrax, smallpox, AIDS or influenza. The fiber-optic-based sensor, which was developed by David Gerdt and John Herr at Empirical Technologies Corporation (ETC) in the US, is aimed at the medical and environmental monitoring market.

This immunoassay technology uses a fiber-optic coupler sensor to detect antigens or antibodies in fluids - such as human blood, saliva or environmental sources - for a range of diseases. Early indications show that this fiber-optic coupler sensor is more sensitive than other technologies available and that it reacts in real-time to the presence of the appropriate analyte. This means the entire process, from set-up to diagnosis, can be completed in five minutes, says BTG.

To use the device, a sample of fluid is taken and then injected into the space immediately surrounding the fiber-optic coupler sensor. The sensor features a pair of singlemode optical fibers which are drawn down to form an evanescent wave sensor. This sensor detects output ratio changes due to molecular activity occurring within the exposed evanescent field of the coupler.

If the fusion joint of the coupler is coated with an immunoassay antibody and then surrounded with a solution containing the conjugate antigen, the sensor will detect the interaction. BTG claims this immunoassay technology is applicable to a broad range of in-vitro tests and offers advantages over existing fiber-optic immunoassay technologies by overcoming issues such as intensity, modal, and phase noise, all of which affect sensitivity of the optical fiber sensor.

Manufacturers will have the option to allow testing for a single disease or screen for multiple diseases simultaneously by using an array of sensors.

BTG is now seeking licensees to develop and manufacture this technology with the expectation that a product could be on the market in 12-24 months.