Fluorescent sensing of reactive oxygen species on the sub-cellular level

While reactive oxygen species are known to play many critical roles in health and disease, it is their sub-cellular localisation that ultimately determines their cellular impact. Small molecule fluorescent sensors have proved to be invaluable tools to study real-time changes in living cells, tissue, and even animal models. For the sensing of reactive oxygen species, a number of strategies have been developed to enable highly selective and sensitive fluorescence imaging. Here we review the various methods to achieve sub-cellular targeting of fluorescent reactive oxygen species sensors, with particular focus on cases that have been used to study endogenous reactive oxygen species and employed in in vivo studies.