Borgolte, MaxMaxBorgolteQuint, IsabelIsabelQuintKaiser, LarsLarsKaiserCsuk, RenéRenéCsukDeigner, Hans-PeterHans-PeterDeigner2023-01-192023-01-192022https://publica.fraunhofer.de/handle/publica/41907610.3390/diagnostics12061380Kynurenine is a tryptophan metabolite linked to several inflammatory processes including transplant failure, a significant challenge in transplant medicine. The detection of small molecules such as kynurenine, however, is often complex and time consuming. Herein, we report the successful synthesis of a fluorescently labelled kynurenine derivative, showing proper fluorescence and anti-kynurenine antibody binding behavior in a magnetic bead immunoassay (MIA). The fluorescent kynurenine–rhodamine B conjugate shows a KD-value of 5.9 µM as well as IC50 values of 4.0 µM in PBS and 10.2 µM in saliva. We thus introduce a rapid test for kynurenine as a potential biomarker for kidney transplant failure.enTransplant failureTransplant medicineBiomarkerFluorescent probesFluorescenceKynurenineAmino acidsRapid testingjournal article