Ultrasensitive detection of carcinoembryonic antigen in nipple discharge via magnetic-field amplified

The large decline in breast cancer mortality has been driven by rapid development and continuous progress in diagnostic techniques. However, it remains difficult to diagnose malignant lesions in distal branching ducts using mainstream techniques such as immunofluorescence ultrasound, molybdenum target, and ductoscopy. Combined with existing reports, we found that CEA level by ELISA in 13 patient 's nipple aspirate fluids (NAF) may be positively correlated with the malignancy of breast lesions. Here, considering the low content of CEA in NAF and the need for automated techniques for batch clinical testing, a magnetic induced mixing surface-enhanced Raman spectroscopy technique (SERS) was used to quantitatively analysis CEA concentration in NAF. In the appearance of CEA, an antibody-conjujated silver nano-probe (AgNPs-Ab1/4-ABP) can be linked onto the surface of another antibody-conjujated magnetic-probe. This immune sandwich-like structure enables more AgNPs-Ab1/4-ABP to remain in situ in the magnetic field. The magnetic spontaneous collection effect brings second SERS signal amplification at 1140 cm −1 approximately. After testing 10 clinical samples, the signal of Magnetic-Field Amplified SERS was not affected by the complex components in NAF, and a good linear range of 0.5–20 ng mL −1 could be achieved. This method might potentially be useful in the differential diagnoses of benign lesions with breast cancer and clinical follow-up of non-surgical intervention nipple discharge patients.