A new method for senescent cell detection, based on lipofuscin labeling with a fluorescent reporter through a biorthogonal strain-promoted azide-alkyne cycloaddition (SPAAC), is described. The sensing protocol involves a first step where the interaction of lipofuscin with a Sudan Black B derivative containing an azide moiety (SBB-N3) is carried out. In the final step, the azide moiety reacts with a fluorophore containing a cyclooctine ring (BODIPY). The efficacy of this two-step protocol is assessed in senescent melanoma SK-MEL-103 cells, senescent triple-negative breast cancer MDA-MB-231 cells, and senescent WI-38 fibroblasts. In all cases, a clear fluorescence pattern was observed in senescent cells, compared to proliferative cells, only when the SBB-N3-BODIPY probe was formed. Our results provide an alternative tool for the detection of senescent cells, based on an in situ bio-orthogonal reaction for lipofuscin labeling.