Sample/reagent adsorption on alumina versus Pyrex substrates of microfabricated electrochemical sensors
| Autor: | Kwong Yue Hui, Chung-Chiun Liu, Richard Diefes, Laurie Dudik, Miklós Gratzl |
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| Rok vydání: | 1996 |
| Předmět: |
Chemistry
Potentiometric titration Metals and Alloys Analytical chemistry chemistry.chemical_element Substrate (chemistry) Condensed Matter Physics Electrochemistry Surfaces Coatings and Films Electronic Optical and Magnetic Materials Adsorption Redox titration Reagent Materials Chemistry Electrical and Electronic Engineering Platinum Instrumentation Microfabrication |
| Zdroj: | Sensors and Actuators B: Chemical. 30:133-136 |
| ISSN: | 0925-4005 |
| Popis: | Platinum redox sensors have been microfabricated for potentiometric detection in diffusional microtitration of microliter-size fluid samples. Two different materials, alumina ceramic and Pyrex glass, have been studied for their suitability as sensor substrates. Adsorptions of reagent and/or sample on an alumina ceramic substrate and a Pyrex glass substrate are compared. Using iodimetric redox titration, significant adsorption of both reagent and sample occurs on alumina ceramic substrates. This causes contamination and cross-contamination of samples, leading to highly irreproducible results. Reproducibility with a 1.6% coefficient of variation has been achieved using a platinum redox sensor deposited on a Pyrex substrate for the analysis of 20 μL sample microdroplets. Due to the large surface area relative to the small sample volume, surface processes can have a significant effect on the analysis of microsamples. Therefore, precautions must be taken to minimize problems arising from air interference and sensor/sample, sensor/reagent and reagent/sample interfaces. |
| Databáze: | OpenAIRE |
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