Pad-printed Prussian blue doped carbon ink for real-time peroxide sensing in cell culture

Hydrogen peroxide has important roles within cellular functions, as a prevalent form of Reactive Oxygen Species, detection within mammalian cells is of metabolic importance; typically requiring cell lysis or fluorescence-based methods to quantify.

Herein, we explore the novel use of Prussian blue mediated, pad printed carbon electrodes to allow the indirect detection of cellular peroxides in bulk culture media, which facilitates non-invasive, real-time detection.

Electrodes demonstrated capacity to detect H2O2 with a linear range of 1-200 μM in CMEM (R2 = 0.9988), enabling detection of peroxides found in culture media and lysate. Developed electrodes had a Limit of Detection (LOD) of 0.41 μM H2O2 in Britton-Robinson Buffer (BRB), 0.38 μM in Eagle's Minimum Essential Medium (EMEM) and 9.19 μM in Dulbecco's Modified Eagles Medium (DMEM). Electrodes were tested in a conventional 5% serum supplemented EMEM (CMEM) and demonstrated an LOD of 0.5 μM and LOQ of 0.9 μM.

The results demonstrate proof of concept for monitoring H2O2 in complex culture media with potential long-term use and reusability using simple, pad printed Prussian Blue / Carbon electrodes. The lack of further modification, and cost-effectiveness of these disposable electrodes could offer great advancement to monitoring of peroxides in complex media.