Abstract: Provided herein are compounds or fluorogenic probes which can be used as reagents for measuring, detecting and/or screening ROS or RNS such as peroxynitrite or hypochlorite. Provided also herein are methods that can be used to measure, directly or indirectly, the amount of peroxynitrite or hypochlorite in chemical samples and biological samples such as cells and tissues in living organisms. Specifically, the methods include the steps of contacting the fluorogenic probes disclosed herein with the samples to form one or more fluorescent compounds, and measuring fluorescence properties of the fluorescent compounds. Provided also herein are high-throughput screening fluorescent methods for detecting or screening peroxynitrite or compounds that can increase or decrease the level of peroxynitrite or hypochlorite in chemical and biological samples.