Marco Rolandi reported in Nature Communications the development a protonic field effect transistor (H+-FET) that controls the flow of protons instead of electrons, making it a good potential starting point for bio-interface devices. In maleic chitosan nanofibers, protons hop along the hydrated nanofiber hydrogen bond network following the Grotthuss mechanism. The H+ flow is measured with PdHx proton transparent contacts, and this flow is turned on or off by an electrostatic potential applied to a gate electrode.
Photoresponse of a strongly correlated material
Using scanning photocurrent microscopy on suspended VO2 nanobeams, David Cobden and Xiadong Xu have determined that photo-thermoelectric effects dominate photocurrent generation in this strongly correlated material known for a dramatic metal-insulator transition at 68 oC. These results, reported in Nature Nanotechnology, bring us a step further in understanding the fundamental optoelectronic response of strongly correlated electronic systems for developing novel optoelectronic and photonic devices.
Rapid identification of pathogenic bacteria
Qiuming Yu has developed a new technique for rapid identification of marine pathogens based on surface-enhanced Raman scattering (SERS). The technique employs a unique quasi-3D plasmonic nanostructure composed of a gold thin film with subwavelength nanoholes on top and gold nanodiscs at the bottom. The arrays were designed with strong local electric field at the top gold nanoholes, enabling sensitive and reproducible detection of large analytes like bacteria. SERS barcode signatures were generated for pathogenic strains allowing unknown samples to be rapidly identified.