Very recently, studies have been reported on gold nanoclusters quenched by Cu2+ asfluorescent probe for the detection of bilirubin [3,22]. In this perceptive, we explored BSAstabilized CuNCs quenched with Fe3+ as fluorescence Turn On detection for bilirubin. Thesensitivity and selectivity of the developed probe was evaluated with different probableco-existing biomolecules. The performance was assessed in real samples also. The fabricatedCuNCs based Turn On sensor can be developed for a commercially viable point of caredetection method adaptable in primary health care centres