Fabrication of electrochemiluminescence aptasensor for PD-L1 detection based on luminescent CdS@Ce-MOF@Au

Abstract

The expression of programmed death ligand 1 (PD-L1) is closely related to the immune escape of tumor cells, and it is considered as an emerging biomarker due to its immune checkpoint protein properties in clinical diagnosis. Herein, an electrochemiluminescence (ECL) aptasensor based on cerium (Ce) metal–organic frameworks (Ce-MOF) loaded CdS quantum dots (QDs) and gold nanoparticles (Au NPs) was designed to detect PD-L1. The prepared nanorod cluster-like Ce-MOF could well load CdS QDs and improve the ECL intensity and stability. The adsorbed Au NPs expedited electron transport on the electrode surface, thereby further promoting the ECL reactions. In addition, Au NPs facilitated the connecting of PD-L1 aptamer. The constructed ECL aptasensor showed good analysis capability in the presence of H2O2 co-reactant, with a wide linear detection range of 1 pg mL−1 to 100 ng mL−1 and a low detection limit of 0.54 pg mL−1, besides high selectivity and simplicity. It has been applied for the effective detection of PD-L1 in real samples, with satisfactory results.