Theranostic Potential of an NAD(P)H‐Activatable Fluorophore: Assessing Cancer Aggressiveness and Triggering Apoptosis

ABSTRACT Molecular theranostics, integrating precise diagnosis with targeted therapy, represents a cornerstone of personalized medicine. As a pivotal metabolic cofactor, reduced nicotinamide adenine dinucleotide (phosphate) (NAD(P)H) is intrinsically linked to cancer progression and survival when dysregulated. In this study, we report DE‐CQ , an NAD(P)H‐activatable fluorophore that enables both cancer imaging and apoptosis. DE‐CQ allows the real‐time quantification and visualization of intracellular NAD(P)H, serving as a robust molecular indicator of cancer malignancy. Beyond its diagnostic utility, DE‐CQ preferentially induces mitochondria‐ and ER stress‐dependent, caspase‐mediated apoptosis in aggressive MDA‐MB‐231 cancer cells while maintaining minimal toxicity toward normal cells. Our findings demonstrate that DE‐CQ functions as a potent theranostic agent, simultaneously providing diagnostic insights into cancer aggressiveness and triggering cell death. Given its dual functionality and high selectivity, DE‐CQ holds significant potential as a next‐generation platform for advanced, personalized cancer treatment.