Multifunctional Nanoparticles-Key for Optimizing Chemical Nanosensors

摘要

Multifunctional nanoparticles are key for optimizing the performance of chemical sensor devices. We have fabricated a variety of nanosensor devices based on ultrathin metal oxide films and nanowires, which have been integrated on CMOS-based micro-hotplate chips. These sensors have been functionalized with metallic as well as bimetallic nanoparticles. We have demonstrated that Pt-NPs or NiPt-NPs, strongly increase the sensitivity to carbon monoxide and suppress the cross selectivity to humidity in case of SnO₂ thin film based devices. We have employed both nanoparticles synthesized in solution, which are ink-jet deposited, as well as nanoparticles, which are implemented by gas phase synthesis directly on the micro-hotplate chips. The Pt-functionalized SnO₂-thin film sensors show a strongly increased response to CO, which is almost independent of humidity as compared to the bare SnO₂-thin film sensor. The highest response of more than 90% has been achieved with NiPt-functionalized SnO₂-thin film sensors at a very low operation temperature of only 150°C.