Impedimetric detection of carcinoembryonic antigen using a pencil-graphite electrode integrated into a 3D-Printed...

In the present work, we present a 3D-printed mini electrochemical cell designed using polylactic acid (PLA) filament. This platform incorporates a fully integrated electrochemical cell, where the working, reference, and counter electrodes are entirely fabricated from pencil graphite electrodes (PGE). A Reference electrode for the three-electrode system was obtained by applying conductive silver ink onto a pencil graphite electrode. In this study, an electrochemical immunosensor was developed for the detection of carcinoembryonic antigen (CEA). The sensor surface was functionalized using appropriate chemical agents, followed by the immobilization of Anti-CEA for specific recognition. CEA determination was performed by monitoring the interactions on the sensor surface with the Electrochemical Impedance Spectroscopy (EIS). Combined with a 3D-printed electrochemical cell, the CEA immunosensor exhibited a linear response to CEA from 4.0 ng mL^-1 to 250 ng mL^-1 with a detection limit (LOD) of 1.2 ng mL^-1. Also, the proposed immunosensor was successfully applied for CEA detection in commercial human urine samples, achieving CEA detection recoveries ranging from 93 % to 98 %. The developed electrochemical biosensor shows promise for accurately detecting CEA in real samples, providing a precise method that could be valuable for clinical tumor detection.