Designing fluorescent molecular probes with longer wavelength emission (above 600 nm)features towards exclusive detection of CN− ion is highly challenging and rarely found in the field of fluorescent sensors. The contribution here reports a unique chemodosimetric design approach for selective sensing of CN− ion, in both solution and solid states. Towards this, we have utilized an orange emitting fluorescent probe (R1)(λ emission > 600 nm), where the fluorophore is threaded by a fluorene derivative. The bulky fluorine unit regulate the interaction between the fluoropore units to minimize aggregation caused quenching (ACQ). Upon introducing CN− ion, even in the presence of several other ions, intramolecular charge transfer (ICT)from the donor (phenothiazine)to the acceptor (cyanovinyl unit)was completely blocked in the covalently threaded fluorescent moiety and as a result the fluorescence was completely quenched. More importantly, the present system retained its fluorescence properties in the solid state and hence was utilized to detect CN− ion in the solid state through fluorescence quenching mechanism, which enabled the fabrication of a test kit for on-site analysis of CN− ion. DFT and TD-DFT calculations towards validating the experimental results were also performed in order to study the changes caused in the electronic properties of R1 before and after complexation with CN− ion. © 2019