A self-reinforced luminescence signal amplification strategy to construct electrochemiluminescence immunosensor for carcinoembryonic antigen sensing

Abstract

Carcinoembryonic antigen (CEA) is a disease biomarker that reflects the presence of various cancers and tumors in the human body. Sensitive detection of CEA concentration in the blood is beneficial for the clinical diagnosis and treatment evaluation of cancer. Electrochemiluminescence (ECL) sensors used for disease pre-screening are usually subjected to various complex chemical modifications for real-time analysis and detection of CEA concentration in the blood. The ECL behavior of a novel self-reinforced ECL complexes Zn-MOF-Ru-TEA coreacting at the anode is reported in this paper. The self-reinforced ECL complexes Zn-MOF-Ru-TEA are synthesized using one-pot method. Compared with the redox reaction of TEA in the PBS buffer, the energy and charge transport distance provided by Ru(bpy)32+ and TEA molecules in the pore size of Zn-MOF are greatly shortened, so the ECL efficiency of Ru(bpy)32+ is effectively improved. The Cu+/Cu2+ ion pair cycle in the signal label CuNiOS/Au NPs can react with TEA enriched in Zn-MOF-Ru-TEA to produce more reactive radicals, which realizes the amplification strategy of the ECL signal caused by Cu+-triggered probes. Under optimal conditions, the linear range of CEA detection is 10−5 ng·mL−1 to 80 ng·mL−1, and the detection limit is 3.43 fg·mL−1. This is the first time that a Ru(bpy)32+/TEA self-reinforced ECL system has been proposed for CEA detection, which has the advantages of low limit of detection and high sensitivity and offers the potential for the application of sensitive determination of biomarkers.