Label-free electrochemical immunosensors based on Cu-Ni metal–organic framework and carbon nanotube composite for carcinoembryonic antigen detection

Abstract

Monitoring cancer biomarkers is of great significance in clinical diagnosis. In this work, a label-free MWCNTs-COOH/CuNi-BTC/FTO electrochemical immunosensor was developed to quantitatively detect carcinoembryonic antigen (CEA). The bimetallic CuNi-BTC showed enhanced current than singe Ni-BTC, and the addition of the MWCNTs-COOH increased the conductivity and further amplified the current signal. The electrode was further modified with CEA antigen (Ag) and bovine serum albumin (BSA) was used to block the non-specific binding sites. Using the emplified current signal of CuNi-BTC, CEA was detected by a DPV method through the current change caused by the specific recognition reaction of Ag and Ab. Under optimal conditions, a range of 0.80–140 ng/mL and a detection limit of 0.046 ng/mL for CEA was obtained. This electrochemical immunosensor possessed good selectivity, reproducibility and long-term stability.