Scientific research activity is focused on three main lines: ZnO nanowires based gas sensors; porous silicon based sensors and biosensors; hybrid silicon-graphene based light sensors.
ZnO-NWs are synthesized by hydrothermal technique on different substrates (glass, flat silicon, flexible plastic, and optical fiber) for applications in biosensing and gas monitoring. In particular, fabrication and characterization of a chemoresistive gas sensor working at low temperature has been demonstrated. The sensor consists of a silicon substrate with a snake geometry Al heather for recovery mode, the ZnO-NWs as active material and an interdigitated Au electrode for sensing. For biosensing application, the activity is focused on the interaction between proteins and biomodified ZnO-NWs, grown on specific substrates. Optical label-free technique monitoring PL emission of ZnO-NWs under laser irradiation is used to transduce biomolecular interactions.
Multi-layered optical and electrical transducers based on the nanotechnology of porous silicon are designed, fabricated, characterized and integrated in lab-on-chip systems. Porosities between 30 and 85%, pores size from 20nm to 10mm, and specific surface area up to 500 m2/gr can be obtained by electrochemical etching of differently doped crystalline silicon substrates. Dry and wet chemical procedures are used to add specific functionalities, such as biocompatibility, enhanced selectivity, hydrophobicity/hydrophilicity, and photoluminescent emission, to the sponge-like transducers. Applications in biology fundamental studies, medical diagnostic and environmental monitoring have been proved.
The activity concerning physical sensors is mainly focused on the fabrication and characterization of silicon photodetectors working at near infrared wavelengths in both vertically-illuminated and waveguide structures whose efficiency is enhanced by using both optical microcavities and new emerging graphene-like materials. In addition graphene/silicon Schottky junctions are investigated for biosensing applications.
Contact: Luca De Stefano