NSe2 chelating moiety embedded BOPHY probe was synthesized and characterized. The probe displayed high selectivity and sensitivity for the detection of Cu(II). The probe reacted with Cu(II) in less than 1 s and showed a 6 fold increment in fluorescence intensity. Detection limit of the probe was found to be 10.8 nM and the binding ratio of the complex (Probe:Cu(II)) was determined to be 1:1 from the Job's plot. In addition, the probe exhibited reversibility with S2− ions. The probe possessed cell-membrane permeability and sensitive detection of Cu(II) in live HeLa cells with strong green fluorescence.