Prediction of QCM gas sensor responses and calculation of electrostatic contribution to sensor responses using a computational chemistry method

When we construct an odor sensing system using a quartz crystal microbalanc e (QCM) odor sensor array, it is important to know the properties of sensin g films coated on those electrodes and select the optimum combination of se nsors in the array. However, they have not been characterized well enough t o predict the sensor responses without any experiment. Then, we tried to pr edict sensor responses using a computational chemistry method. We have so f ar succeeded in predicting the responses using sensing films of typical liq uid gas chromatography (GC) stationary phase materials to various kinds of gases and a few perfumes. In this study, we calculated the amount of sorbed gas molecules into the typical solid material of GC and the amount of sorb ed perfumes into various sensing films, and it was found that this computat ional prediction method is useful in those cases. Next, we tried to evaluat e the contribution of single interaction energy term to the sorption using this method although it cannot be revealed through the experiment. It was f ound from the results that the contribution of electrostatic interaction to the sorption can almost be evaluated and this calculation method is useful for knowing the properties of gases and sensing films. (C) 2000 Elsevier S cience S.A. All rights reserved.