Despite the importance of H2O2 to human health and disease, the molecular mechanisms of its production, accumulation, trafficking, and function are insufficiently understood due to the lack of sensitive and specific H2O2 sensors that can be used in live cells. The limitations of currently available H2O2-responsive probes include interfering background fluorescence from other ROS, the need for an external activating enzyme, lack of water solubility or compatibility, and/or excitation profiles in the ultraviolet region. OxiVision Green hydrogen peroxide sensor is non-fluorescent and displays no absorption in the visible region. The addition of H2O2 triggers a prompt fluorescence increase with concomitant growth of a visible wavelength absorption band. This probe has a large dynamic range owing to its binary absorption/emission response. The fluorescence response of OxiVision Green hydrogen peroxide sensor is H2O2-selective. OxiVision Green hydrogen peroxide sensor exhibits a >100-fold selectivity for H2O2 over similar ROS such as O2-, NO, or OCl.