Ionophore-Containing Siloprene Membranes: Direct Comparison between Conventional Ion-Selective Electrodes and Silicon Nanowire-Based Field-Effect Transistors

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• 作者：Anping Cao ; Marleen Mescher ; Duco Bosma ; Johan H. Klootwijk ; Ernst J. R. Sudh枚lter ; Louis C.P.M. de Smet
• 刊名：Analytical Chemistry
• 出版年：2015
• 出版时间：January 20, 2015
• 年：2015
• 卷：87
• 期：2
• 页码：1173-1179
• 全文大小：364K
• ISSN：1520-6882

文摘

Siloprene-based, ion-selective membranes (ISMs) were drop-casted onto a field-effect transistor device that consisted of a single-chip array of top-down prepared silicon nanowires (SiNWs). Within one array, two sets of SiNWs were covered with ISMs, each containing two different ionophores, allowing the simultaneous sensing of K and Na ions using a flow cell. It is shown that both ions can be effectively detected in the same solution over a wide concentration range from 10p>鈥?p> to 10p>鈥?p> M without interference. The ISMs were also analyzed in a conventional ISE configuration, allowing a direct comparison. While the responses for Kp>+p> were similar for both sensor configurations, remarkably, the Nap>+p> response of the ISM-covered SiNW device was found to be higher than the one of the ISE configuration. The addition of a Nap>+p> buffering hydrogel layer between the SiO₂ of the SiNW and the ISM reduced the response, showing the importance of keeping the boundary potential at the SiO₂/ISM interface constant. The responses of the siloprene-covered SiNW devices were found to be stable over a period of at least 6 weeks, showing their potential as a multichannel sensor device.