Knowledge about the importance of fluoride ions in biological and medical processes has grown in recent years. It is now known that this anion plays a role in dental health and has potential use for the treatment of osteoporosis. Fluoride is easily absorbed by the body but is excreted slowly. Fluoride also plays an important role in a number of military applications. For example, the refinement of uranium in nuclear weapons manufacturing utilizes fluoride. GB, more commonly known as sarin (isopropyl methylphosphonofluoridate), is a nerve agent employed by the Aum Shinrikyu cult in terrorist attacks in Tokyo in 1995. Over the past two decades, a large number of optical sensors have been developed for detecting fluoride. For the most part, the methods employed in these sensors rely on strong interactions taking place between Lewis-acidic boron and fluoride, as well as hydrogen bonding and other types of interactions involving fluoride as a participant or a disrupter. In addition, reaction-based chemodosimeters have been devised for the selective detection of fluorides.