A solid-state electrochemiluminescence biosensor for Con A detection based on CeO2@Ag nanoparticles modified graphene quantum dots as signal probe

A solid-state electrochemiluminescence (ECL) biosensor for the detection of concanavalin A (Con A) was constructed using graphene quantum dots (GQDs) as luminophore, which were loaded on polyamidoamine (PAMAM) functionalized CeO 2 @Ag NPs by the interaction between the NH 2 of PAMAM and the COOH of GQDs. The electrodepositing gold layers were used as matrix to immobilize glucose oxidase (GOx). GOx served as recognition elements to further capture Con A by the specific interaction between carbohydrate and Con A. With the increase of the concentration of Con A, the amount of GOx-CeO 2 @Ag-GQDs incubated onto the electrode was increased and a higher ECL signal was obtained. The constructed biosensor exhibited a sensitive response towards Con A and a low detection limit of 0.16 pg/mL was obtained. Such a construction strategy provides a new approach for applying GQDs to establish a solid-state ECL biosensor.