<p>High-sensitivity luminescence nanoprobes for biomolecule identification are important in clinical diagnostics and biological analysis. Since bilirubin is a key indicator of liver function, early and accurate detection is essential for diagnosing and monitoring liver disease. In this study, we developed a red-light-emitting Europium (Eu) molybdate complex using a single-step, room-temperature technique, exhibiting unique photostability. When the bilirubin is added, a decrease in the luminescence of the synthesized Eu-molybdate complex is observed in a linear range of 9.96 to 58.8 µM. The detection limit and quantification limit were calculated to be 0.211 µM and 0.76 µM, respectively. The nanoprobe we developed exhibits exceptional selectivity and sensitivity to bilirubin, even in the presence of other biomolecules and ions. Furthermore, bilirubin can be measured in both blood and urine using this method.</p> Graphical Abstract <p></p>