Arginine-engineered gold nanoclusters for doxorubicin chemiluminescence sensing

Arginine surface-engineered 6-aza-2-thiothymine gold nanoclusters (Arg/ATT-AuNCs) via host-guest assembly were synthesized which exhibit exceptional catalytic activity and intense photoluminescence. Arg/ATT-AuNCs enhanced the CL intensity from NaIO₄-H₂O₂ system by 1200-fold. The CL mechanistic studies revealed that Arg/ATT-AuNCs not only accelerated decay of H₂O₂ to form reactive oxygen species, but also acted as efficient energy acceptors of singlet oxygen (¹O₂) via a CL resonance energy transfer (CRET) pathway. It was observed that doxorubicin (DOX) quenches the CL signal through an inner filter effect that disrupts the CRET process. Based on this, a straightforward, rapid, and highly sensitive biosensor has been developed for the detection of DOX in human serum samples, achieving a low detection limit of 0.029 µM. The biosensor was applied to DOX determination in human serum samples with recoveries ranging from 91.1 to 106.2%. This study not only provides a new method for the detection of DOX, but also broadens the application scope of AuNCs in the field of CL.