RESUMO
The separation of the superimposed electrochemical signals of intracellular guanine (G) and xanthine (X) is difficult, which is great obstacle to the application of cell electrochemistry. In this paper, independent functional modules, G-functional module (G-FM) and X-functional module (X-FM), were constructed by molecular imprinting technology for sensitive detection of G and X without mutual interference, then integrated in dual-functional module cellular electrochemical sensing platform (DMCEP) as signal sensing units. DMCEP transmitted signals of G and X in cells synchronously to two windows by two signal sensing channels, and achieved the separation of superimposed signals of G and X in cells. DMCEP exhibited satisfactory reproducibility with relative standard deviation (RSD) of 3.10 and 2.22 %, repeatability with RSD of 3.72 and 3.05 % for G and X detection, and detection limit 0.05 µΜ for G and 0.06 µΜ for X. Good linear relationships between cell concentrations and the signals of G and X on DMCEP were shown in range of 0.75-85 × 106 and 3-85 × 106 cells/mL, respectively. The growth of MCF-7 cells was tracked by DMCEP, and showed consistent trend with the cell counting method, while the change of cell viability from lag to logarithmic phase captured by DMCEP was earlier than that of cell counting method. This strategy provided the foundation for the establishment of the cell viability electrochemical detection method, and new insights into the simultaneous recording of other analyses with superimposed peak positions and the simultaneous tracking of multiple biomarkers.