Carbonyl sulphide (COS) monitoring on MOS sensors for biomedical applications

Resistive metal-oxide semiconductor (MOS) sensors have been tested in the monitoring of carbonyl sulphide (COS), a biomarker for acute rejection (AR) in lung transplanted patients. COS concentration in the breath of these patients (about 0.5 ppm) is in fact more higher than that found in healthy peoples, making possible the real time diagnosis of this pathology by breath analysis. In2O3-based MOS resistive sensors have been therefore tested at different temperatures and COS concentrations in order to optimize the sensor response and response/recovery time. The ultimate aim of this work is to develop a simple and cost-effective breath test for the acute rejection in lung transplanted patients.