Multiplexed aptasensor for simultaneous detection of carcinoembryonic antigen and mucin-1 based on metal ion electrochemical labels and Ru(NH3)63+ electronic wires.

In this paper, a dual-target electrochemical aptasensor has been developed for simultaneous detection of carcinoembryonic antigen and mucin-1 based on metal ion electrochemical labels and Ru(NH3)63+ electronic wires. When targets are present, the interaction between targets and their respective aptamers leads to the dissociation of double-strand DNA because the targets have higher affinity to its aptamer than the complementary strand. And the qualitative and quantitative analyses of the two targets are realized by the differential pulse voltammetry (DPV) peaks generated by metal ion electrochemical labels. For the effective loading of a large number of metal ions, Au/bovine serum albumin (Au/BSA) nanospheres are employed as carriers to develop Au/BSA-metal ions. After Ru(NH3)63+ complexes are embedded into double-strand DNA to form the electronic wires, the electrical conductivity and the electron transfer of the detection system are greatly improved. The detection limit of the proposed assay was calculated as 3.33fM ranging from 0.01pM to 100nM. Therefore, this novel sensing assay provides a new and sensitive platform for detecting several targets simultaneously in biochemical research and clinical diagnosis.