A hydrogen peroxide sensor for exhaled breath measurement

An increase in hydrogen peroxide concentration in exhaled breath (EB) of patients, who suffer from some diseases related to the lung, function, has been observed and considered as a reliable indicator of lung diseases. In the EB of these patients, hydrogen peroxide is present in the vapour phase together with water, thus one of the approaches of monitoring hydrogen peroxide in the EB is to condense it and then to perform the hydrogen peroxide measurement in the condensate. Earlier, a hydrogen peroxide sensor based on an electrolyte metal oxide semiconductor field-effect transistor ((MOSFET)-M-E) has been investigated. The sensor shows the possibility to measure hydrogen peroxide at a concentration of micro-molar level. Due to its miniaturizability, the sensor is able to detect hydrogen peroxide in a small volume and is thus especially suitable for monitoring of hydrogen peroxide in the EB. In this paper, a simple set-up for condensation of hydrogen peroxide in the EB is introduced. The set-up consists of a cooling tube using a Peltier element for condensation of the exhaled breath air and the (MOSFET)-M-E-based hydrogen peroxide sensor. Using this cooling tube, primary results on the collection and measurement of hydrogen peroxide in artificial EB are given. (c) 2005 Elsevier B.V. All rights reserved.