Recent Advances in Chemosensors Bearing Pyrazole and Imidazole Rings: An Approach Toward the Detection of Metal Ions Based on these Diazoles

The optical detection of metal ions via ligand‐metal interactions has attracted attention in recent years, driven by advances in organic dyes and the crucial role of metals in nature and industry. Aza‐heterocyclic compounds (AHCs) are promising dyes for this purpose due to their tunable electronic properties and metal‐coordinating ability. Among these, pyrazole and imidazole rings have been explored as recognition and signaling units in fluorescent and colorimetric probes. They offer coordination capacity, stability, and notable synthetic accessibility, making them particularly attractive for developing efficient chemosensors. Metals are common analytes in biological, environmental, and materials sciences; for example, excess metal ions can cause serious ecological and health problems, underscoring the need for efficient and selective recognition methods. In general, pyrazole and imidazole derivatives are promising scaffolds for developing more efficient and selective probes for sensing metal ions; this contribution focuses on representative probe examples with these two ring types reported in the last 5 years.