Aptamer-based nanofilter interface for small-biomarker detection with potentiometric biosensor

In this paper, we report the concept of an aptamer (Ap)-based nanofilter interface for suppression nonspecific signals generated by interfering species in biological samples. As a model target small biomolecule, l-3,4-dihydroxyphenylalanine (l-DOPA) is used to demonstrate its electrical discrimination from dopamine (DA) despite their similar chemical structures using DA–Ap nanofilter-coated Au gate field-effect transistor (FET). A electrode employed assess response FET l-DOPA on basis oxidative reactions. particular, proposed based layer immobilized at aryl-diazonium-based anchor monolayer, which electrochemically grafted via diazonium chemistry. result, signal clearly discriminated that DA concentration 1 ?M or higher FET. That is, trapped through formation complexes, molecular charges are shielded counter ions not contact with surface, whereas reaches and reacts generating regardless nanofilter. The surface properties modified investigated cyclic voltammetry, chronocoulometry, atomic force microscopy, X-ray photoelectron spectroscopy. platform biosensor Ap-based contributes monitoring biomarkers while suppressing