▎ 摘　　要

In the present work, we investigated a label-free fluorescence resonance energy transfer (FRET) based poly (aspartic) acid (PAsP) functionalized graphene quantum dot (PAsP-GQDs) immunosensor for the selective and sensitive sensing of MAGE-A11 antigen. Synthesis of GQDs was accomplished with hydrothermal carbonization of Onion hull (ONI-GQDs).Synthesized PAsP-GQDs were characterized for fluorescence performance, functional compositions and morphological analysis. To form a typical FRET system, functionalized GQDs conjugated with anti-MAGE-A11 (antibody) using EDC/NHS chemistry served as an energy donor, while graphene nanosheets served as energy acceptors (quenchers). The fabricated PAsP-GQDs@M-A11-Ab immunosensor demonstrated high selectivity to MAGE-A11 with a broader detection range about of 0.05 ng mL-1 - 5 mu g mL-1 (R2 = 0.9906) and a detection limit of about of 5.6 pg mL-1, with a rapid response time of 12 min. The performance of the developed immunosensor was established using real sample analysis, which showed an average recovery of 96.8 % with % RSD 0.71 indicating the high precision and reproducibility of the method. Furthermore, to implicate the post-functionalization modifications, cellular bioimaging potential and cytotoxicity studies were conducted as a comparative assessment. The present immunosensing strategies can be utilized as an analytical tool for detecting MAGE-A11 in various cancers.