Determination of d(+)glucose, d(+)mannose, d(+)galactose or d(-)fructose in a mixture of hexoses and pentoses by use of dental plaque coupled with a glass electrode.

A potentiometric sensor has been developed by coupling dental plaque with a flat-surface glass electrode. Selectivity of this electrode for hexoses and pentoses has been tested. The electrode responds linearly to beta-d(+)glucose, d(+)mannose, d(+)galactose and beta-d(-)fructose over a narrow concentration range between 10(-4) and 10(-3)M, but has negligible response to the other hexoses and pentoses. This "plaque" electrode, using live bacterial cells, may serve as a model for the development of other selective electrodes for carbohydrates.