The diagnosis of infectious diseases, the monitoring of environment and detection of potential bioterrorism agents greatly require a pathogen identification method with better combined speed, accuracy and sensitivity. Here, a kind of novel cell-based biosensors based on measurement of fluorescence is introduced, which could detect pathogens and other antigens by measuring fluorescent signals within minutes. It is based on the specifically bind character of antigens and antibodies and the theory of bioluminescence or chemiluminescence. The cell could emit light via calcium chemically fluorescent indicators such as Fluo-4, or calcium fluorescent proteins such as aequorin, green fluorescent protein. B cell-based biosensors and mast cell-based biosensors have been applied in some fields. This kind of biosensors has advantages in combined sensitivity, accuracy and speed, while it also has disadvantages such as cross reactivity and problems with cellular storage and maintenance. This is a promising kind of biosensors applied in the diagnosis of infectious diseases, the monitoring of environment and detection of potential bioterrorism agents.