Neurodegenerative Disease Diagnosis via Ion‐Level Detection in the Brain

Metal ions are heavily involved in the membrane potential and intracellular activities of cells. Increasing evidences have shown that it is critical to evaluate the ion levels and monitor their dynamic changes in the brain for the diagnosis of neurodegenerative diseases (NDDs), including Alzheimer's disease, Parkinson's disease, Huntington disease, amyotrophic lateral sclerosis, and so on. Herein, the roles of metal ions in the occurrence and development of NDDs are intensively discussed, and the recent advances in probes and sensors for ion‐level detection are summarized. Finally, the further applications of ingenious ion‐selective probes and sensors are outlined, highlighting the future opportunities for the metal ion‐based diagnosis of NDDs.