This system consists of two components, a biotin‐modified tetrazine‐substituted PS and a cyclic EGFR‐targeting peptide linked with a bicycle[6.1.0]non‐4‐yne dienophile, which are preferentially internalized only by cancer cells expressing both biotin receptors and EGFR, followed by a rapid bio‐orthogonal inverse electron‐demand Diels‐Alder reaction to form the corresponding cycloadduct, thereby restoring the PS's ability to fluoresce and generate ROS.208. Here, EGFR is linked to cancer.