Research progress of small molecule fluorescent probes for ferrous ion and heme

Small molecule fluorescent probes have gained widespread attention for their advantages of high selectivity, sensitivity, and easy to operate, and have played a critical role in the detection of various species. They have also demonstrated great potential in the field of biomedical research. Iron, as the most abundant transition metal in the human body, plays a vital role in many physiological functions. Due to the influence of the reductive microenvironment of cell, ferrous ion (Fe²⁺) is the main component of labile iron in living cells. Heme, consisting of Fe²⁺ and protoporphyrin IX, is one of the main signaling molecules that wrap biological iron in the human body, and also participates in many physiological and pathological processes. Therefore, the development of small molecule fluorescent probes for detecting Fe²⁺ and heme as effective monitoring tools will help to further understand their pathological and physiological functions, with potential applications in other fields. This review summarizes the research progress of small molecule fluorescent probes for Fe²⁺ and heme detection in recent years, and provides insights into future directions for their development.