Detection of Liquid Organic Solvents on Metal Oxide Nanostructure Decorated Porous Silicon Interfaces

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• 作者：Caitlin Baker ; James L. Gole
• 刊名：ACS Sensor
• 出版年：2016
• 出版时间：March 25, 2016
• 年：2016
• 卷：1
• 期：3
• 页码：235-242
• 全文大小：537K
• ISSN：2379-3694

文摘

We study the interaction of liquid organic solvents within the pores of n- and p-type porous silicon (PSi) interfaces. Several polar (acetone, methanol, ethanol, isopropanol, and water), borderline (chloroform), and nonpolar (toluene and isoprene) molecular solvents have been characterized on distinct n- and p-type pore structures, as analyzed using scanning electron microscopy. Fundamental to these studies has been the generation of Nyquist diagrams comparing the behavior for both dry and solvent treated interfaces for each system studied. The results of these studies on an undecorated PSi interface suggest a closer correlation with the dipole moments associated with the applied organic solvents rather than their dielectric response. This is supported by the observed interaction of the considered solvents with metal oxide (Au_xO (x ≫ 1) and SnO_x) decorated PSi interfaces where nanostructured metal oxide-solvent dipole–dipole interactions appear to be manifest. In correlation with the Nyquist plots and the establishment of equivalent circuit models, we evaluate the real-time capacitance and conductance. These studies suggest the viability of array-based sensing for the considered organic solvents.