Designing and synthesis of suitable turn-on fluorescence sensors for monitoring intercellular Cr3+ is limited due to fluorescent quenching of paramagnetic Cr3+ and lack of Cr3+ selective multichelating ligand functionalities. To overcome the limitations related with the earlier developed methods, a fluorescent pyrene-based probe have been synthesized that selectively differentiate Cr3+ from alkali, alkaline earth metals and most of transition metals including Fe3+ ratiometrically in aqueous media. Interaction of Cr3+ with probe bring pyrene moieties close enough to have better aligned p-p stacking, which enhanced the excimer peak many fold. While the interaction of all other metals bring a insignificant difference in stacking, resulted a slight change in fluorescence intensity. Exceptional selectivity of probe with Cr3+ has been confirmed by density functional theory (DFT) studies in addition to experimental results. Confocal fluorescence microscopic imaging of HeLa cells revealed that probe can be used to monitor Cr 3+ in live cells to map its subcellular monitoring.