Intracellular Hydrogen Peroxide Detection with Functionalised Nanoelectrodes

Abstract

Abstract Hydrogen peroxide (H 2 O 2 ) is one of the most important reactive oxygen species, and it is involved in a number of cellular processes ranging from signal transduction to immune defence and oxidative stress. It is of great interest to intracellularly quantify H 2 O 2 to improve the understanding of its role in disease processes. In this study, we present an amperometric nanosensor for the quantification of H 2 O 2 at the single‐cell level. Deposition of the electrocatalyst Prussian Blue on carbon nanoelectrodes enables selective H 2 O 2 reduction at mild potentials. Owing to their small size and needle‐type shape, these nanoelectrodes can penetrate the membrane of single living cells, causing only minimal perturbation. The nanosensors allow for the monitoring of penetration‐induced oxidative outbursts as well as the uptake of H 2 O 2 from the extracellular environment in single murine macrophages.