In recent years, research on disease-related substances has made remarkable progress, and it has become clear that they play an important roles in cancer, immunoreceptors, fertilization, development/differentiation, infectious diseases, biopharmacy development, and the like. Since the amount of disease-related marker substances present in the living body is very small, the development of a new evaluation technique is required. The authors have developed new compounds that have both a fluorescent substance with high environmental responsiveness, which was originally developed, and a substance (peptide, etc.) that has a high affinity for disease-related substances, neurotransmitters, and the like. Furthermore, when the organic fluorescent substance was modified on the surface of an inorganic material, such as magnetic particles, and various concentrations of the disease-related substance were added, a change in the fluorescence intensity and high-sensitivity detection of the disease-related substance by using magnetic beads were achieved. In this paper, we introduce such materials developed by the author with an emphasis on the viewpoint of analytical chemistry.