(Invited) Dual Functional Platinum Black-modified Miniaturized Electrodes for Hydrogenperoxide Detection

Abstract

Microelectrochemistry has a long history in the life sciences for in vivo and in vitro measurements ofe.g., pH, oxygen, and signaling molecules such as nitric oxide (NO), adenosine-5`-triphosphate (ATP),hydrogen peroxide (H2O2) and neurotransmitters. In particular, gaining information on signalingmolecules at live cells, e.g., during and after stimulation is of significance for understanding cellsignaling. Within recent years, our research team has focused on the development of micro-sizedsensing approaches for the detection of ATP [1,2], which is considered among the most importantautocrine and paracrine signaling molecules [3]. H2O2 belongs to the group of reactive oxygen species(ROS), which is in contrast to radical ROS rather stable. H2O2 is involved in many physiologicalprocesses such as hypoxic signal transduction, cell differentiation and proliferation but is also involvedin mediating immune responses [4]. The effect is, among other parameters, dependent on its localconcentration and its exposure time.Platinum black is a highly suitable electrocatalytic nanomaterial for the electrochemical detection ofH2O2 [5]. We recently demonstrated that Pt black modified microelectrodes can be used for H2O2 atgranulocytes and peripheral blood mononuclear cells from pigs [6]. Within this presentation, we willintroduce dual functional miniaturized probes that allow further miniaturization of electrochemicalsensors for biomedical applications. We will demonstrate that these probes have great potential for cellmeasurements, i.e., at macrophages that produce and release ROS in response to phagocytosis orstimulation.