A novel sandwich-type SERS immunosensor for selective and sensitive carcinoembryonic antigen (CEA) detection.

Monitoring the malignant tumors via cancer biomarkers is very significant process. Nonetheless, the practical clinical applications need selective and sensitive analytical methods/techniques. In this study, a novel sandwich type immunosensor based on surface-enhanced raman scattering (SERS) was presented including 4-mercaptobenzoic acid labeled MoS2 nanoflowers@Au nanoparticles (MoS2 NFs@Au NPs/ MBA) as CEASERS tag and Fe3O4@Au nanoparticles functionalized delaminated Ti3C2Tx MXene (Fe3O4 NPs@Au NPs/d-Ti3C2TX MXene) as SERS magnetic supporting substrate for carcinoembryonic antigen (CEA) detection. Especially, the determination of single molecule by using SERS method enables early diagnosis of major diseases. In addition, this technique can be utilized for multiplex analyzes owing to narrow well-resolved peaks. The prepared CEASERS tag and SERS magnetic supporting substrate were characterized by scanning electron microscope (SEM), x-ray diffraction (XRD) method, x-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and fourier transform infrared spectroscopy (FTIR). A linearity of 0.0001-100.0 ng mL-1 was observed with high sensitivity. Finally, sandwich type immunosensor demonstrated good selectivity and stability for target CEA recognition in plasma sample.