Development of QCM sensors modified by AlPO4-18 films

A new type of sensor, namely a quartz crystal microbalance (QCM) modified by a layer of AlPO4-18 crystals has been developed and tested in gas sensing applications. Different sensor configurations (coating by AlPO4-18 films or by individual particles) and preparation procedures are discussed. The performance of the sensor has been compared to that of other QCM devices modified by different zeolite materials (zeolite A and silicalite). The AlPO4-18 modified sensor presents a sharp response to water and is nearly insensitive to propane. This allows the sensing of moisture in mixtures where hydrocarbons are also present.