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

Abstract 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 (Ab 1 ) as the main ALV-J sensing platform. For signal amplification, pH-responsive hollow MnO 2 (hMnO 2 ) nanospheres encapsulating Ru(bpy) 3 Cl 2 and carrying secondary antibodies (Ab 2 ) were employed. Under optimal conditions, the immunosensor exhibited a wide ALV-J detection range of 10 1.80 to 10 4.30 TCID 50 /mL (TCID 50 : 50% tissue culture infective dose) and a low detection limit of 10 1.71 TCID 50 /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.