&lt;p style="margin: 0px 0px 13px;"&gt;Chemiresistors based on ultrathin platinum nanowires (PtNWs, ~3 nm in diameter) exhibit ultrahigh sensitivity towards hydrogen gas, with about two orders of magnitude increase in response compared with PtNW sensors fabricated via top-down approach. In addition, by rational surface engineering, we show that the sensitivity and selectivity of ultrathin PtNWs can be tailored by design. A significantly reduced cross-sensitivity towards humidity was achieved by ligand engineering that incoporates separation and detection down to the nanoscale, and other sensing characteristics of the ultrathin PtNWs can also be optimized by tailoring surface conditions using an on-chip electrochemical approach. Further exploiting the chemical (surface) sensitivity of nanomaterials that can be transformed into electrical signals, we have employed integrated and comprehensive on-chip nanoelectronic signaling approaches as new tools for the fundamental study of important chemical and biological catalytic systems. In specific, we have developed an on-chip electrical transport spectroscopy (ETS) approach for directly probing the electrochemical surfaces of metallic nanocatalysts under in operando conditions, using ultrathin PtNWs as model electrocatalysts. Our results not only show a high degree of consistency with generally accepted conclusions in platinum electrochemistry, but also provide important insights into various technically important electrocatalytic reactions. This study defines a novel nanoelectronic on-chip characterization strategy, as an alternative to the traditional spectroscopic characterization techniques, for in situ electrochemical surface studies with high surface sensitivity and surface specificity. The on-chip nanoelectronic investigations have further been applied to investigate the charge transport mechanism and the electrochemical behavior in electrogenic microbes (including Shewanella and Geobacter), which has been a subject of on-going debate. Our results elucidate the complex basis of electrical conductivity of both individual microbial cells and biofilms, and have led to a new model revealing the electrochemical origin of microbial conductivities. &lt;/p&gt;

Nanoelectronic signaling approaches for chemical sensing and fundamental investigation of chemical/biological systems

253rd National Meeting (2017)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.