Model of vapor-induced resistivity changes in gold-thiolate monolayer-protected nanoparticle sensor films.
Model of vapor-induced resistivity changes in gold-thiolate monolayer-protected nanoparticle sensor films.
复制标题
DOI：
10.1021/ac070068y
复制
发表时间：
2007-05
影响因子：
7.4
通讯作者：
W. H. Steinecker;M. Rowe;E. Zellers
中科院分区：
文献类型：
--
作者：
W. H. Steinecker;M. Rowe;E. Zellers
研究了由有机蒸气吸附诱导的正辛硫醇单层保护的金纳米颗粒 (MPN) 薄膜的电荷传输调节。导出的模型允许根据汽膜分配系数、分析物密度和介电常数预测 MPN 涂层化学电阻 (CR) 响应。使用从 CR 阵列和平行厚度剪切模式谐振器收集的 28 种化合物的蒸气进行校准，以验证模型中固有的假设并评估其性能。结果提供了对蒸气-MPN 相互作用的性质的深入了解，包括表观膜膨胀效率的系统变化，并表明该模型通常可以将 CR 响应预测在 24% 以内。使用不同尺寸的 CR，发现蒸气敏感性在 104（器件面积 x MPN 层厚度）范围内几乎与 MPN 薄膜体积无关。对于两种传感器类型，灵敏度与分析物蒸气压成反比，但 CR 传感器可提供显着更高的信噪比，对于几种测试的分析物，计算出的检测限在十亿分之一的低浓度范围内。考虑了这些结果对于将 MPN 涂层 CR 阵列用作微分析系统中的检测器的影响。
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.