Bacterial Spore Detection by [Tb³⁺(macrocycle)(dipicolinate)] Luminescence

Dipicolinic acid (DPA) is a unique constituent of bacterial spores, a dormant form of Bacillus and Clostridium, which can be detected using DPA-triggered Tb³⁺ luminescence. [Tb(DO2A)]⁺ improves the sensitivity of bacterial spore detection over Tb³⁺(aq) owing to the exclusion of coordinated water molecules and represents the first step toward construction of a DPA receptor site with enhanced binding selectivity. The title ternary [Tb(DO2A)(DPA)]^- complex was structurally characterized and features two DO2A-DPA interligand hydrogen interactions that stabilize the complex.