Electrosynthesis of molybdenum carbide-doped epitope-imprinted conductive polymers for the determination of soluble suppression of tumorigenicity 2 with a field effect transistor platform.

In this work, several peptides of soluble suppression of tumorigenicity 2 (sST2) were screened, synthesized, and then imprinted with electropolymerization onto poly(aniline-co-3-aminobenzenesulfonic acid), poly(AN-co-MSAN). Three MXenes, including titanium or molybdenum carbides, were also doped within the conductive polymer film to enhance the electrochemical response. The electrodes were employed as the extended gate in a field-effect transistor (EG-FET) platform. The sensing range and limit of detection for sST2 were found to be from 1.0 fg/mL to 100.0 pg/mL and 0.05 fg/mL, respectively. Importantly, incorporation of a Mo-based MXene increased the responsivity of the FET sensor by a factor of about 1.5 at pg/mL to ng/mL sST2 concentrations. This study demonstrated the potential utility of an sST2-imprinted electrochemical sensor for diagnostics.