Sorptive properties of monolayer-protected gold nanoparticle films for chemical vapor sensors and arrays

IEC 253

Jay W. Grate, Pacific Northwest National Laboratory, P.O. Box 999, Richland, WA 99352
Nanoparticles and nanoparticle-based materials are attracting great interest for their unique properties and potential for application in diverse areas. Monolayer-protected nanoparticles (MPNs) are of particular interest because they can be taken up in solution, synthetically modified, or cast into thin films. On chemical microsensors, these materials act as sorptive films. The thickness shear mode device has been used to investigate the vapor uptake properties of several readily prepared gold MPN materials. It is demonstrated that many, but not all, MPN-based sensing layers provide rapid and reversible uptake of vapors, as is desirable for vapor sensors. Sorptive selectivity varies with the monolayer structure, which provides a basis for sensing material design and use in sensor arrays. The sorptive properties are compared with more common polymeric sorptive materials so that conclusions can be reached regarding the relative roles of sorption and transduction in MPN-coated sensor performance.