NO donors are routinely used as the exogenous source in in vitro studies. However, the kinetics or the dose of NO release from the existing donors is not readily monitored. This complicates the elucidation of the involvement of NO in a biological response. We report herein a series of NO donors (NOD545a-g), whose NO release is triggered by UV light at 365 nm or a two-photon laser at 740 nm, and importantly, their NO release is accompanied by a drastic fluorescence turn-on, which has been harnessed to follow the kinetics and dose of NO release in a real-time fashion with spectroscopic methods or microscopic methods in in vitro studies. These merits have rendered NOD545a-g useful molecular tools in NO biology.