Electrochemical neuron-specific enolase (NSE) immunosensor based on CoFeO@Ag nanocomposite and AuNPs@MoS/rGO.

Small cell lung cancer (SCLC) is highly associated with the risk of early metastasis. Neuron-specific enolase (NSE), a biomarker of SCLC, is directly related to tumor burden and early diagnosis. This biomarker exists in nerve tissue and neuroendocrine tissue. In this study, an electrochemical NSE immunosensor based on gold nanoparticles modified molybdenum disulfide and reduced graphene oxide (AuNPs@MoS/rGO) as the electrode platform and CoFeO@Ag nanocomposite as the signal amplification was developed. The immobilization of anti-NSE capture antibody was successfully performed on AuNPs@MoS/rGO modified electrode surface by amino-gold affinity and the conjugation of anti-NSE secondary antibody on CoFeO@Ag nanocomposite was successfully completed by the strong esterification reaction. The final immunosensor was designed by the specific interactions of electrode platform and signal amplification. The fabricated nanocomposites and electrochemical immunosensor were characterized by both physicochemical characterization techniques including transmission electron microscopy (TEM), scanning electron microscopy (SEM), x-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS), fourier transform infrared spectroscopy (FTIR), and electrochemical methods such as cyclic voltammetry (CV), square wave voltammetry (SWV), and electrochemical impedance spectroscopy (EIS). The quantification limit (LOQ) and the determination limit (LOD) were computed to be 0.01 pg mL and 3.00 fg mL, respectively. In brief, it can be speculated that the constructed electrochemical NSE immunosensor can be successfully utilized in the early diagnosis for lung cancer.