A novel electrochemical immunosensor for carcinoembryonic antigen based on Cu-MOFs-TB/polydopamine nanocarrier

Carcinoembryonic antigen (CEA) is a typical biomarker for lung cancer. It is very urgent to develop a sensitive and rapid method to assay CEA content in human serum. In this work, Cu-MOFs nanomaterials were synthesized by a hydrothermal method . Toluidine blue (TB) loaded mesoporous Cu-MOFs with polydopamine (PDA) coating were employed as a signal probe. The proposed sandwich immunosensor was fabricated by Cu-MOFs-TB/PDA, chitosan and MWCNTs on the glassy carbon electrode with a large surface area to immobilize primary antibodies (Ab 1 ) and provide excellent conductivity. The sensitivity improvement of this new strategy was based on the destruction of the probe and the immune complex by HCl, which resulted in the closer distance between TB and the sensing electrode. Under optimal conditions, CEA was quantitatively detected with a wide linear range from 20 fg mL −1 to 200 ng mL −1 , a low detection limit of 3.0 fg mL −1 (S/N = 3). In addition, the method showed good stability, selectivity, and reproducibility, which possessed wide potential applications for the detection of other tumour biomarkers.