Rhodamine B hydrazide is widely used as a fluorescent probe in biochemical and analytical research. Its strong fluorescence properties make it ideal for detecting and imaging metal ions, particularly copper and mercury, in environmental and biological samples. It is also employed in the development of sensors for reactive oxygen species (ROS) and other analytes due to its high sensitivity and selectivity. In cell biology, it serves as a staining agent for tracking cellular processes and visualizing specific molecules within cells. Additionally, it is utilized in the synthesis of fluorescent dyes and markers for various scientific applications, including diagnostics and molecular imaging.