A unique 3D luminescent metal-organic framework, namely [Cd(L)(H₂O)_0.5]·DMF·2.5H₂O (1), where H₂L=3-(tetrazol-5-yl)triazole, has been successfully prepared and characterized. The framework has demonstrated excellent luminescence properties and structural stability in the water system. Notably, the luminescence intensity of 1 was significantly quenched by Cr(Ⅵ) (1 mL of Cr₂O₇^2- or 150 μL of CrO₄^2-, 1 mmol·L^-1), leading to the formation of an "on-off" luminescence silencing system (Cr₂O₇^2-@1), which was capable of accurately detecting Cr(Ⅵ) in the water system. The primary mechanism responsible for luminescence quenching was the Forster resonance energy transfer (FRET) process. Additionally, by removing the involvement of the FRET process, the luminescence intensity of the Cr₂O₇^2-@1 system could be restored, allowing for the highly selective and sensitive detection of ascorbic acid (AA) in water systems. Moreover, it has been demonstrated that 1 can successfully detect AA in vitamin C tablets, yielding recovery rates ranging from 98.20% to 103.33% and relative standard deviations (RSDs) ranging from 1.78% to 3.42%. Based on the findings of this experiment, a luminescent "IMPLICATION" molecular logic gate has been constructed utilizing AA and Cr(Ⅵ) as the chemical inputs, respectively.