Towards Optically Induced Semiconductor Gas Sensor: Sensing of Acetone

Abstract

Breath analysis is in use since a long history as a part of medical diagnostics. Idea that some of the diseases are characterised by a specific odour was already known since the Hippocrates time. Modern breath analysis has significantly developed comparing to the discovery of the several hundred different VOCs in the common human breath [1] to more than a thousand different VOCs [2]. Regrettably, lack of specificity and selectivity of the semiconductor sensors lead to complications sensing to differ between those compounds for modern semiconductor. Accordingly, it may be a challenge to give right diagnosis to a patient.

To improve such a drawback, a new approach of sensing was provided. Using n- doped semiconductor and the spotlight lamp as an optical irradiation source have shown a possibility to sense different concentrations of acetone vapour. Measured signal maximal increment relative to air in the presence of acetone is 17% (measurement uncertainty 0,72%). It is possible clearly distinguish between healthy and diabetic patients. Thus present way of stimulation may be used to increase level of acetone sensing.