Organic field-effect transistor platform for label-free single-molecule detection of genomic biomarkers.

The rising interest for technologies capable to track a biomarker down to the physical limit points towards new opportunities in early diagnostics of progressive diseases. Indeed, single molecule detection technologies are foreseen to enable clinicians to associate a biomarker tiniest increase to the progression of a disease, particularly at its early stage. Bioelectronic organic transistors represent an extremely powerful tool to achieve label-free and single-molecule detection of clinically relevant biomarkers. These electronic devices are millimetric in size and in the future could be mass produced at low-cost. A key component of electrolyte-gated field-effect transistors, also addressed as Single-Molecule with a large Transistors (SiMoT), is a self-assembled monolayer attached to the gate comprising a highly-packed layer of recognition elements. So far, only the SiMoT detection of proteins, using the corresponding antibodies as recognition element, has been reported. In this study, for the first time, the SiMoT sensing response towards genomic biomarkers is proposed. Herein, the gate is functionalized with a genomic biomarker for multiple sclerosis (miR-182). This is relevant, not only because single molecule detection limits are demonstrated, but also because it proves that the SiMoT label-free single molecule detection principle is the only one of his kind that can detect, by means of the same platform, both protein and genomic markers.