Understanding the electrolyte background for biochemical sensing with ion-sensitive field-effect transistors
| Autor: | Kristine Bedner, Vitaliy A. Guzenko, Oren Knopfmacher, Mathias Wipf, Michel Calame, Ralph L. Stoop, Wangyang Fu, Alexey Tarasov, Christian Schönenberger |
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| Rok vydání: | 2012 |
| Předmět: |
Silicon
Materials science Transistors Electronic Supporting electrolyte Nanowire Oxide Analytical chemistry General Physics and Astronomy Metal Nanoparticles 02 engineering and technology Electrolyte Biosensing Techniques 010402 general chemistry 01 natural sciences law.invention chemistry.chemical_compound Electrolytes Adsorption law General Materials Science Computer Simulation Transistor General Engineering Equipment Design 021001 nanoscience & nanotechnology 0104 chemical sciences Equipment Failure Analysis chemistry Models Chemical Ionic strength Field-effect transistor 0210 nano-technology |
| Zdroj: | ACS nano. 6(10) |
| ISSN: | 1936-086X |
| Popis: | Silicon nanowire field-effect transistors have attracted substantial interest for various biochemical sensing applications, yet there remains uncertainty concerning their response to changes in the supporting electrolyte concentration. In this study, we use silicon nanowires coated with highly pH-sensitive hafnium oxide (HfO(2)) and aluminum oxide (Al(2)O(3)) to determine their response to variations in KCl concentration at several constant pH values. We observe a nonlinear sensor response as a function of ionic strength, which is independent of the pH value. Our results suggest that the signal is caused by the adsorption of anions (Cl(-)) rather than cations (K(+)) on both oxide surfaces. By comparing the data to three well-established models, we have found that none of those can explain the present data set. Finally, we propose a new model which gives excellent quantitative agreement with the data. |
| Databáze: | OpenAIRE |
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