An immunosensor using functionalized Cu2O/Pt NPs as the signal probe for rapid and highly sensitive CEA detection with colorimetry and electrochemistry dual modes

Abstract Compared with single response systems, dual-mode sensors have attracted much attention due to their high accuracy and high sensitivity. In this work, we successfully combined the high sensitivity of the electrochemical analysis method with the simplicity and rapidity of colorimetric analysis technology to construct a device that can accurately and quickly detect CEA in dual mode. The device in platinum nanoparticles (Pt NPs) loaded on an octahedral cuprous oxide (Cu2O) surface has excellent peroxidase performance. Using Cu2O/Pt NPs as a signal tag can not only generate a larger response current in electrochemical mode but also effectively catalyze 3,3',5,5'-tetramethyl benzidine (TMB) color development in colorimetric mode. The results show that the dual mode sensor has good detection performance. Using the electrochemical analysis method, the detection range was 0.1 pg/mL - 80 ng/mL, and the detection limit was 0.03 pg/mL. The detection range of colorimetric analysis technology was 0.1 ng/mL - 80 ng/mL, and the detection limit was 0.026 ng/mL. Therefore, the dual-mode sensor has excellent detection performance, good selectivity, reproducibility and stability and provides a new detection method for early cancer detection and prognosis monitoring.