Two stochastic sensors based on graphene powder modified with platinum and titanium dioxide (TiO2Pt/rGO) and 2,6-bis((E)-2-(furan-2-yl) vinyl)-4-(4,6,8-trimethylazulen-1-yl) pyridine (S1) and 2,6-bis((E)-2-(thiophen-3-yl) vinyl)-4-(4,6,8-trimethylazulen-1-yl)pyridine (S2) were proposed for the assay of three biomarkers monitorized in colon cancer: P53, KRAS and CEA. The limits of determinations were low, and the sensitivity very high. Whole blood samples from confirmed colon cancer patients were used for the validation of the method. (C) 2017 The Electrochemical Society. All rights reserved.