Studies of Redox Processes in Cells
I. Lähdesmäki Y. K. Park, A. D. Carroll, M. Decuir and J.Ruzicka, Analyst, 2007, 132, 811

Live cells produce H2O2 in response to cellular stress. H2O2 is harmful to cells and may play a role in cellular apoptosis and senescence. Catalase is an enzyme that breaks down H2O2, and has been suggested as a key component of the cellular defense mechanism against oxidative loads. In order to study the rate of H2O2 decomposition by live cells, a voltammetric setup was assembled in LOV.

By using  mercury as the working electrode material, the detection of O2 and H2O2 was possible from a single voltammetric scan. Mouse embryonic fibroblast cells were grown on Cytodex beads and packed into the LOV flow cell, next to the working electrode (~10^4 cells / 5 µL bead column). The results revealed that catalase-overexpressing cells decomposed H2O2 more rapidly than wild type cells. (Lähdesmäki 2007).