Molecular probes is a class of molecules or molecular assemblies designed to interact specifically with a target entity, such as a biomolecule, ion, or cellular structure, and report on this interaction, often via a detectable signal. This methodological approach investigates the presence, location, state, or quantity of specific targets within complex systems. Key characteristics include high specificity for the target and the incorporation of a reporter group (e.g., fluorophore, radioisotope, enzyme). Molecular probes are fundamental tools across diverse scientific disciplines, including biology, chemistry, and medicine, enabling critical research, diagnostic, and therapeutic applications by providing non-invasive or minimally invasive means to study molecular processes.