An electrochemical sensor array and its application to real‐time brain slice imaging

Abstract

AbstractAn electrochemical sensing system using a planar microelectrode array has been developed for monitoring biological molecules with relatively high spatial and temporal resolution. This allows noninvasive real‐time imaging of biological molecules released from tissue. In this study, we establish a multichannel hydrogen peroxide (H2O2) sensing system to monitor the real‐time H2O2 distribution in tissue using a planar sensor array. H2O2 is known to be associated with the pathology of neurological diseases because it is a by‐product of degenerative reactions involving reactive oxygen species, which are a major cause of oxidative stress in mammalian cells. The sensor array is based on a 64‐channel ITO electrode array composed of 50 × 50 μm electrodes modified with an enzyme (horseradish peroxidase) and an electron transfer mediator. We place a cultured rat hippocampal slice on the array and measure the current at each sensor using a multipotentiostat. When we introduce bicuculline into the solution as a stimulant in the presence of a catalase inhibitor, we can observe a distinct increase in the H2O2 concentration. This real‐time H2O2 distribution monitoring system is a powerful tool with which to explore the neuronal cell death mechanism in biological systems. © 2009 Wiley Periodicals, Inc. Electron Comm Jpn, 92(9): 1–6, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecj.10140