A novel chemiluminescence sensor for alpha-fetoprotein detection based on an aptamer–luminol modified magnetic graphene oxide and copper-based MOF composite

Abstract

Herein, an aptamer–luminol modified magnetic graphene oxide and copper-based MOF composite was prepared and used to build a novel target-triggered “turn on” chemiluminescence (CL) sensor for alpha-fetoprotein (AFP) detection. Magnetic graphene oxide (MGO) was functionalized with the complementary sequence of the AFP aptamer (cDNA), and then MGO-cDNA was linked to aptamer modified luminol (Apt–luminol) through the complementary base pairing effect. The functionalized magnetic graphene oxide (MGO-cDNA/Apt–luminol) was prepared as a specific magnetic separation and signal switch material. ZnONPs-Au@CuMOFs shows excellent catalytic performance and was used as a catalyst for the luminol–H₂O₂ reaction. AFP will specifically recognize and bind to Apt on MGO-cDNA/Apt–luminol when AFP is present, which causes luminol release and triggers the CL reaction. The released luminol encounters ZnONPs-Au@CuMOFs and produces strong CL intensity. Therefore, a novel target-triggered “turn on” CL method with high selectivity and sensitivity for detecting AFP has been established. The linear range and detection limit were 1.0 × 10⁻⁴–50 ng mL⁻¹ and 4.2 × 10⁻⁵ ng mL⁻¹, respectively. The sensor also exhibited good selectivity, reproducibility and stability, and was finally used for AFP detection in serum samples.