Biological functions and detection strategies of magnesium ions: from basic necessity to precise analysis

Magnesium is a ubiquitous element in the natural environment and plays an indispensable role in various biological processes in living organisms. This review focuses on the diverse functions of magnesium ions (Mg²⁺) in living cells, particularly emphasizing their role in the immune and cardiovascular systems. We discuss how Mg²⁺ regulates key cellular processes, including enzyme catalysis, cellular signaling and nucleic acid structural stabilization, and explore the adverse effects of magnesium imbalance, which has been associated with numerous diseases ranging from cardiovascular to neurological disorders. Given these critical functions, accurate measurement of Mg²⁺ is essential. Thus, we also summarize a variety of analytical techniques for Mg²⁺, ranging from traditional methods like atomic absorption spectrometry and electrochemical sensors to emerging approaches, such as fluorescent probe methods and X-ray fluorescence strategies. Bringing together recent advances in Mg²⁺ detection with a deeper understanding of its biological role, this review aims to promote the systematic integration of Mg²⁺ research in biomedical and clinical practice, in particular in the field of disease diagnosis and treatment.