Possibilities and Challenges for Quantitative Optical Sensing of Hydrogen Peroxide

Hydrogen peroxide (H2O2) plays a key role in many biological processes spanning from coral bleaching, over cell signaling to aging. However, exact quantitative assessments of concentrations and dynamics of H2O2 remain challenging due to methodological limitations— especially at very low (sub μM) concentrations. Most published optical detection schemes for H2O2 suffer from irreversibility, cross sensitivity to other analytes such as other reactive oxygen species (ROS) or pH, instability, temperature dependency or limitation to a specific medium. We review optical detection schemes for H2O2, compare their specific advantages and disadvantages, and discuss current challenges and new approaches for quantitative optical H2O2 detection, with a special focus on luminescence-based measurements. We also review published concentration ranges for H2O2 in natural habitats, and physiological concentrations in different biological samples to provide guidelines for future experiments and sensor development in biomedical and environmental science.