“…However, these methods often rely on trained operators, expensive equipment, and tedious preprocessing, despite providing accurate and satisfactory results. Electrochemical sensors have attracted great attention due to their superiority of high sensitivity, outstanding selectivity, fast response, easy integration, and in situ monitoring, which have been developed into powerful analytical tools in the fields of environmental protection and biomedicine. − To enhance the electrochemical sensing performance of iron, a variety of nanomaterials are developed and assembled on the electrode to introduce multifunctions, such as catalysis, surface coordination, separation, preconcentration, switching, and target recognition . On the basis of the complexation and preconcentration, dimethyliminocinnamyl-linked rhodamine and a kind of imine receptor prepared from 4,4′-diaminodiphenymethane and 2-hydroxy-5-nitrobenzaldehyde have been reported and modified on the substrates to provide nitrogen atoms as donor species to bind Fe 2+ , respectively, showing excellent selectivity and outstanding quantitative capability.…”