Multimode microsensors based on Ag–TiO 2 –graphene materials used for the molecular recognition of carcinoembryonic antigen in whole blood samples

Ag–TiO 2 –graphene pastes modified with inulin, and l -alanine tert -butyl ester nitrate ( l -Ala-C 4 - l -Lac), respectively, were proposed for the molecular recognition of carcinoembryonic antigen (CEA) from whole blood samples. High levels of CEA are associated with different types of cancer, one of them being colorectal cancer. Both sensors gave high reliability for the measurements, and also high sensitivity and selectivity were recorded. The modes used were stochastic mode for qualitative and quantitative analysis of CEA, and differential pulse voltammetry for the quantitative measurement of CEA. The lowest limit of determination (20.5 fg mL −1 ) was recorded when the multimode sensor based on Ag–TiO 2 –graphene paste was modified with the inulin IQ.