New biosensor platform supports multiple applications

Tokyo--Toshiba Corporation today announced that it has developed essential technology for an advanced biosensor chip capable of wide-ranging applications. Experimental biosensors using the technology can detect proteins in blood much more quickly and efficiently than present chemical-based detection methods, and can measure glucose in blood with up to 500 times the sensitivity of current biosensors.

A key element of Toshiba's versatile technology is the company's proprietary optical sensing technology, which utilizes a laser and a light-sensitive film. Using different film in the chip allows the technology to be used to detect different substances and to be used in numerous applications. Toshiba is now refining the technology and aims at launching biosensors for use in medical diagnostics, environmental monitoring and food processing in 2004.

Biosensors can detect and measure substances in very small test samples. The basic principle is to induce an enzymatic or organic chemical reaction in the sample and convert that reaction into an electronic signal. One area where they are expected to make their mark is in medicine, in such areas as protein analysis. Proteins in the blood are an invaluable means to diagnosis of a number of diseases, including cancers, but current analytical methods are chemical-based, require a relatively large-scale system, a key drawback, and are time consuming. Several companies are known to be investigating protein biosensors, but quick, compact protein biosensors are not yet in practical use.

Toshiba's biosensor

Toshiba's new biosensor comprises a sensor chip that reacts with the sample and detection section that records the result. The sensor chip has an optical penetration section, fabricated with Toshiba's fine process technology, and an area coated with the sensor film, which induces a reaction with the sample. Tests with biosensors based on the technology have confirmed their superiority to current testing equipment. Used as a glucose sensor, Toshiba's biosensor is up to 500 times more sensitive than currently available glucose sensors, which operate in range of some 10 mg/dL.

It is also faster and more efficient in detecting proteins. Protein identification in clinical laboratories typically uses enzyme-linked immunosorbent assaying. Toshiba's experimental protein biosensor does the same job in just one tenth of the time required for such assaying. In addition, it works with a blood sample 20 times smaller and requires only one tenth of the reagent.

Another advantage of Toshiba's biosensor technology is that it supports miniaturization, making it possible to develop tools for use in the home, as well as in medical facilities and in industrial applications.

The sensing film used in the sensor chip can be changed according to substance to be detected, making Toshiba's biosensor a platform for various applications. Following development of a protein sensor and glucose sensor, Toshiba will continue to expand application, including development of a detection system for allergens in foods, such as egg, and of an environmental assessment system to test for endocrine disrupting pollutants and to monitor air and water purity.