DNA has the genetic information storage and transmission capacity according to the sequential order of the monomer and creates a central role in the chemical evolution by copying itself with the proliferation feature. WatsonCrick base pairs define two base pairs with hydrogen bonds. If metal coordination bonds replace hydrogen bonds more stable alternative metallo-DNA sequence can be established. If the replication feature can be obtained for the metallo-DNA, this will greatly benefit the creation of DNA computer keys. In this study, a new type of benzimidazole based metallo-DNA sensors consisting of a connector unit that unsaturated azinil bridge linked to Watson-Crick base pairs with Ni 2+ , Hg 2+ , Zn 2+ , Ag + , Pt 2+ , Pd 2+ metal cations and a benzimidazole has been designed. Absorption and emission spectrum of the newly designed aqua medium based fluorophore and their metallo-DNA sensors with selected cations have been theoretically investigated by using DFT method. The logic gates of selected possible sensors which response in the visible region have also been examined in detail in acidic and water phase. As a result of calculated absorption-emission spectrum data show that T-Hg-A-Bnz,