Pulsed Electrochemical Detection
Although amperometry is one of the most used detection methods for microchips, it suffers from low signal stability. Because PED used an oxidation/reduction cycle to clean the electrode, each detection step is performed with a brand new surface. We are interested in applying this detection method for the analysis of different phenolic compounds.
By coating gold microwires with carbon paint, we can combine the advantages of the detection geometry with the surface chemistry of carbon. By integrating these electrodes with microchips, LODs of nM have been achieved.
Packed Immobilized Enzyme Reactors
We have recently reported the development of a packed immobilized enzyme reactor (IMER) and its integration to a capillary electrophoresis microchip. The applied procedure involves the separation of the target analyte by capillary electrophoresis (CE), which is then coupled to a post-column IMER that produces H2O2. The H2O2 produced is finally detected downstream at the surface of a working electrode.
Effects of Surfactants on EC Detection
Surfactants are routinely added to the background electrolyte in CE to stabilize the EOF. For the same reason, they interact with the electrode surface. We are interested in understanding the effects of such interactions on the electrochemical response of phenolic compounds.