Investigation of heterogeneous electrochemical processes using multi-stream laminar flow in a microchannel
| Autor: | Melissa S. Hasenbank, Daniel T. Schwartz, Elain Fu, Jeffrey B. Nelson, Paul Yager |
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| Rok vydání: | 2007 |
| Předmět: |
Chemical process
Surface Properties Microfluidics Biomedical Engineering Bioengineering Nanotechnology Electrons Biosensing Techniques Electrochemistry Biochemistry Sensitivity and Specificity Electrochemical cell Molecule Horseradish Peroxidase Microchannel Models Statistical Chemistry Microchemistry General Chemistry Microfluidic Analytical Techniques Surface Plasmon Resonance Enzymes Immobilized Coupling (electronics) Oxygen Models Chemical Gold Biosensor |
| Zdroj: | Lab on a chip. 7(4) |
| ISSN: | 1473-0197 |
| Popis: | A multi-component microfluidic electrochemical cell is shown to be a useful analytical tool for probing complex coupled processes in electrolytic systems. We recently reported an enzymatic signal amplification phenomenon that may provide increased sensitivity when detecting bio-analytes (M. S. Hasenbank, E. Fu and P. Yager, Langmuir, 2006, 22, 7451–7453), but to fully harness this method requires an improved understanding of the underlying electrochemical and chemical processes. We use spatial control of electrolyte streams on patterned conductive substrates in a microfluidic platform to elucidate the coupling of homogeneous chemical steps to heterogeneous electrochemical charge transfer processes. Because the gold surface was observable using SPR imaging, electrochemical phenomena could be monitored optically in real time. Based on these and additional results, we propose a mechanism for the novel amplification phenomenon that involves direct electron transfer between surface-immobilized enzyme molecules and the gold surface. This improved understanding of the underlying mechanism should enable the future implementation of this phenomenon in signal amplification schemes for highly sensitive lab-on-a-chip biosensors. |
| Databáze: | OpenAIRE |
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