A novel pH-responsive electrochemiluminescence immunosensor for ALV-J detection based on hollow MnO2 encapsulating Ru(bpy)3Cl2

A novel pH-responsive sandwich-type electrochemiluminescence immunosensor was successfully developed for the detection of avian leukosis virus subgroup J (ALV-J). The immunosensor consisted of graphene oxide functionalized with tannic acid (rGO-TA) and primary antibodies (Ab1) as the main ALV-J sensing platform. For signal amplification, pH-responsive hollow MnO2 (hMnO2) nanospheres encapsulating Ru(bpy)3Cl2 and carrying secondary antibodies (Ab2) were employed. Under optimal conditions, the immunosensor exhibited a wide ALV-J detection range of 101.80 to 104.30 TCID50/mL (TCID50: 50% tissue culture infective dose) and a low detection limit of 101.71 TCID50/mL (S/N = 3). Importantly, the immunosensor showed high sensitivity, good reproducibility and excellent operational stability. Finally, the immunosensor was evaluated using a real avian serum sample containing ALV-J, with excellent results being achieved.