Such a 3D matrix (grown by CVD) was used to prepare an immunosensor for carcinoembryonic antigen (CEA, a tumor biomarker).149 Briefly, a graphene substrate was used for the polymerization of dopamine, which subsequently served as a matrix for noncovalent Con A immobilization and interaction with HRP‐labeled anti‐CEA as a biorecognition element bound to Con A via a glycan part of HRP. This evidence concerns the gene CEACAM5 and neoplasm.