Two new coordination complexes based on benzimidazole dicarboxylic acid, Zn(Hbidc)⋅H2O (1) and Cd(Hbidc)(H2O) (2), have been synthesized under hydrothermal conditions. The complexes were characterized using elemental analysis, infrared and UV–visible spectroscopies, powder X‐ray diffraction, thermogravimetry and single‐crystal X‐ray diffraction. Structural analyses showed that the crystal structures of 1 and 2 are different, due to the various modes of linking of the benzimidazole dicarboxylic acid. Complex 1 has a two‐dimensional network structure and 2 has a three‐dimensional network structure. In addition, we studied the performance of the fluorescence response of two complexes. Results showed that the complexes can be used as chemical sensors for multifunctional testing, such as for UO22+, xanthine and Fe3+ ions. Even if the concentration is very low, they could also be detected, showing that coordination complexes 1 and 2 have very high fluorescence sensitivity. The detection limit for UO22+ is 5.42 nM (1) and 0.02 nM (2), that for xanthine is 1.37 nM (1) and 0.28 nM (2), and that for Fe3+ ions is 0.76 nM (1) and 0.62 nM (2).