Carcinoembryonic antigen (CEA) is a cancer-related tumor marker, which is commonly used for preventive screening, auxiliary diagnosis, and recurrence monitoring. Therefore, it is of great significance to develop a new CEA detection method. In this paper, we developed an SERS aptasensor for CEA based on silver nanorod array chip, thiol aptamer, and 4-mercaptophenylboronic acid (4-MPBA). The silver nanorod array chip modified by CEA thiol aptamer (aptamer-SH) was used as SERS capture substrates. Ag@4-MPBA was used as a surface-enhanced Raman spectroscopy (SERS) tag. This proposed SERS aptasensor could detect CEA down to 0.447 pg·mL-1 with a wide linear range from 1 pg·mL-1 to 100 ng·mL-1 (R2 = 0.9907). The recovery of the standard addition test for CEA in serum was between 97.25% and 102.67%, and the RSD ≤ 2.52% (n = 3). The sensor has the advantages of good specificity, high sensitivity, and a wide linear range. It provides a new method for the detection of CEA in serum.
Keywords: Ag nanorod array chip; CEA; Carcinoembryonic antigen; SERS; aptamer; sensor; surface-enhanced Raman spectroscopy.