Report on a novel strategy to tackle matrix effects, including nonspecific adsorption and other types of interference of endogenous matrix components, and to detect carcinoembryonic antigen in undiluted blood plasma, at levels below the physiological threshold. The dataset provides relevant raw and processed Data supporting the manuscript "Tackling matrix effects in biosensor-based analysis of untreated blood plasma". The dataset is organized into 6 folders, each named after a Figure in the manuscript or its related Supplementary information. Images are reported in .TIF format, and Data in .txt format. The labels of the axes and the units are indicated in the headers of individual columns of each .txt file.