A compound and method for detecting hypoxic cells and tissue are provided. The compound includes a probe selected from the group consisting of a hypoxia sensitive 2-nitroimidazole containing fluorescence imaging probe, a hypoxia sensitive reversible ON-OFF fluorescence imaging probe, a hypoxia sensitive azo-based fluorescence imaging probe, and combinations thereof. The method includes contacting the cells or tissue with the probe of any one of claims 1-13 and detecting fluorescent intensity of the cell or tissue, wherein increased fluorescent intensity indicates that the cells or tissue is hypoxic. Also provided are a method of synthesizing the compound and a method for synthesizing a therapeutic agent including the compound.