A heterometallic MOF, [Cd6Na4(L)4(DMF)2(μ-H2O)3] (1, H4L = 1,1'-ethylbiphenyl −3,3',5,5'-tetracarboxylic acid), has been synthesized. 1 can detect Ornidazole (ODZ) by fluorescence quenching and Cysteine (Cys) by fluorescence enhancement. The detection limits of ODZ and Cys are 0.32 μM and 19.7 nM, respectively. Then the processed 1 can detect glucose through fluorescence enhancement with a low detection limit. 1 can also encapsulate glucose to form a MOF hydrogel, and the fluorescence is stronger than that of 1. By fluorescence quenching effect, MOF hydrogel can detect Tetracycline (TET) and Metronidazole (MDZ) in water system. The detection limits MOF hydrogel to TET and MDZ are 0.11 and 0.14 μM. The mechanism of quenching is also discussed in the article. Notably, Eu3+ ions can be encapsulated in 1 and Eu3+@CdNa-MOF can emit Eu3+ characteristic red fluorescence. Finally, fluorescent inks are made based on the luminescence characteristics of Eu3+@CdNa-MOF. The color of this ink disappears under HCl atmosphere and reappears under NH3 atmosphere. This phenomenon can be repeated cyclically. Therefore, the Eu3+@CdNa-MOF has great potential applications in anti-counterfeiting.