PDMS/glass hybrid device with a reusable carbon electrode for on‐line monitoring of catecholamines using microdialysis sampling coupled to microchip electrophoresis with electrochemical detection

摘要

Abstract On‐line separations‐based sensors employing microdialysis (MD) coupled to microchip electrophoresis (ME) enable the continuous monitoring of multiple analytes simultaneously. Electrochemical detection (EC) is especially amenable to on‐animal systems employing MD‐ME due to its ease of miniaturization. However, one of the difficulties in fabricating MD‐ME‐EC systems is incorporating carbon working electrodes into the device. In this paper, a novel fabrication procedure is described for the production of a PDMS/glass hybrid device that is capable of integrating hydrodynamic MD flow with ME‐EC using a flow‐gated interface and a pyrolyzed photoresist film carbon electrode. This fabrication method enables the reuse of carbon electrodes on a glass substrate, while still maintaining a good seal between the PDMS and glass to allow for pressure‐driven MD flow. The on‐line MD‐ME‐EC device was characterized in vitro and in vivo for monitoring analytes in the dopamine metabolic pathway. The ultimate goal is to use this device and associated instrumentation to perform on‐animal, near‐real time in vivo monitoring of catecholamines.