Utilizing Bimetallic Nanoparticle-Catalyzed Methylene Blue for Sensitive Detection of CYFRA21-1: A Biomarker for Esophageal Cancer

A highly sensitive electrochemical immunosensor for the detection of CYFRA21-1, a biomarker for esophageal cancer, was developed using bimetallic nanoparticle-catalyzed methylene blue as a signal amplification strategy. Au@Rh dendritic nanocrystals (DNCs) were employed as the sensing platform, while PtPd nanoparticles on polydopamine-modified hollow carbon spheres (PtPd/PDA/HCSs) were used as the signal probe. The immunosensor exhibited a wide linear range of 0.05 to 50 ng/mL, with a low detection limit of 0.01 ng/mL. It also demonstrated good specificity, reproducibility, and accuracy, with recoveries ranging from 96.8 to 104.5% in human serum samples. The presence of interfering substances commonly found in human serum did not significantly affect the immunosensor’s performance, with a relative error of less than 5%. The proposed immunosensor’s analytical performance surpasses other reported methods, making it a promising tool for early diagnosis and monitoring of esophageal cancer in clinical applications.