Abstract
Alpha-fetoprotein (AFP) is a crucial biomarker for detecting certain tumors across various demographics, including men, non-pregnant women, and children. However, existing detection methods often lack the desired sensitivity, necessitating the development of a straightforward, dependable, and highly sensitive AFP detection method. In this study, a novel approach utilizing a sandwich sensor system designed around the GDYO@AuNPs@PCN (graphdiyne oxide, gold nanoparticle, and porous coordination network) composite was proposed. The results revealed that this composite material, comprising three key components, offers superior quenching capabilities and heightened sensitivity to AFP compared to DNA sensors employing different nanomaterials. Leveraging the distinctive advantages and properties of the composite material, a "three in one" structure was devised by integrating two aptamers with AFP to form an efficient "sandwich" configuration for AFP capture. Additionally, the inclusion of antifouling peptides in the system effectively mitigates non-specific adsorption of AFP on the sensing interface, ensuring a high signal-to-noise ratio. Notably, the sandwich sensor employing the "three in one" composite with peptides achieves a limit of detection (LOD) of 1.51 pg mL(-1), indicative of its ability to reduce background signals, facilitate efficient AFP binding, and enhance sensitivity. Furthermore, the sensor exhibited promising performance and demonstrated consistent results in serum samples, emphasizing its promising practical applications.