Ultrasensitive assay of HER1, HER2, and heregulin-α in whole blood

•Stochastic sensors were used for ultrasensitive simultaneous determination of HER1, HER2, and heregulin-α in whole blood.•N-(pyridine-3-yl-methyl) oleamide, and N-(2-mercapto-1H-benzo[d]imidazole-5-yl) oleamide were used as modifiers.•Wide linear concentration range and low limits of determination were recorded. Microsensors based on the physical immobilization of oleamides (N-(pyridine-3-yl-methyl) oleamide, and N-(2-mercapto-1H-benzo[d]imidazole-5-yl) oleamide) on paste containing nanographene decorated with spheroidal Cu were proposed for the molecular recognition and ultrasensitive simultaneous determination of HER1, HER2, and heregulin-α in whole blood. While for the assay of HER1 and HER2 there were not significant differences in the sensitivities recorded when N-(pyridine-3-yl-methyl) oleamide, and N-(2-mercapto-1H-benzo[d]imidazole-5-yl) oleamide were used to modify the nanographene paste, for the assay of heregulin-α, a higher sensitivity was recorded when N-(2-mercapto-1H-benzo[d]imidazole-5-yl) oleamide was used to modify the paste. Wide working concentration ranges were recorded for HER1 (between 10−13 and 10−8 mol L − 1), HER2 (between 10−12–10−10 mol L − 1), and heregulin-α (10−13–10−11mol L − 1). The student t-test showed that there is no significant difference between the results obtained by utilizing the two microsensors for screening tests of whole blood, at 99% confidence level. [Display omitted]