| Title: | Model of vapor-induced resistivity changes in gold-thiolate monolayer-protected nanoparticle sensor films |
| Author(s): | Steinecker WH; Rowe MP; Zellers ET; |
| Address: | "Engineering Research Center for Wireless Integrated MicroSystems, Department of Chemistry, University of Michigan, 109 South Observatory, Ann Arbor, Michigan 48109-2029, USA" |
| ISSN/ISBN: | 0003-2700 (Print) 0003-2700 (Linking) |
| Abstract: | "An investigation of the modulation of charge transport through thin films of n-octanethiolate monolayer-protected gold nanoparticles (MPN) induced by the sorption of organic vapors is presented. A model is derived that allows predictions of MPN-coated chemiresistor (CR) responses from vapor-film partition coefficients, and analyte densities and dielectric constants. Calibrations with vapors of 28 compounds collected from an array of CRs and a parallel thickness-shear-mode resonator are used to verify assumptions inherent in the model and to assess its performance. Results afford insights into the nature of the vapor-MPN interactions, including systematic variations in apparent film swelling efficiencies, and show that the model can predict CR responses typically to within 24%. Using CRs of different dimensions, vapor sensitivities are found to be virtually independent of the MPN film volume over a range of 104 (device-area x MPN layer thickness). Sensitivities vary inversely with analyte vapor pressure similarly for the two sensor types, but the CR sensor affords significantly greater signal-to-noise ratios, yielding calculated detection limits in the low-part-per-billion concentration range for several of the analytes tested. The implications of these results for implementing MPN-coated CR arrays as detectors in microanalytical systems are considered" |
| Keywords: | "Absorption Algorithms *Biosensing Techniques Calibration *Gases Gold/*chemistry *Membranes, Artificial Models, Theoretical Nanoparticles/*chemistry Organic Chemicals/*chemistry Pressure Sensitivity and Specificity Sulfhydryl Compounds/*chemistry Surface P;" |
| Notes: | "MedlineSteinecker, William H Rowe, Michael P Zellers, Edward T eng R01-OH03692-06/OH/NIOSH CDC HHS/ Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S. Research Support, U.S. Gov't, P.H.S. 2007/05/26 Anal Chem. 2007 Jul 1; 79(13):4977-86. doi: 10.1021/ac070068y. Epub 2007 May 25" |
