A molecularly imprinted electrochemical aptasensor-based dual recognition elements for selective detection of dexamethasone.

In this work, a novel molecularly imprinted electrochemical aptasensor (MIEAS) was developed for highly selective detection of dexamethasone (Dex) in natural water environment. Gold nanoparticles (AuNPs) modified by nitrogen doped molybdenum carbide-graphene (N–Mo 2 C-Gr) were employed as the supports, where N–Mo 2 C-Gr improved the conductivity of the electrode and provided a larger specific surface area to polymerize more active substances. Using Dex as template molecule, o-phenylenediamine (o-PD) as the chemical functional monomer and aptamer as the biofunctional monomer, a molecularly imprinted polymer (MIP) membrane with Dex specific recognition sites was formed by electropolymerization. Due to the synergistic effect of MIP and aptamers, the as-prepared MIEAS exhibited a decent linear relationship to Dex detection within a relatively wide range of 10−13 – 10−5 M, and the detection limit was 1.79 × 10−14 M. The recovery in actual water and tablet samples is satisfactory, which confirms the potential application prospects of this sensor in the determination of Dex. [Display omitted] • A molecularly imprinted electrochemical aptasensor was designed for the detection of Dex based on dual recognition elements. • Aptamer was used as the biofunctional monomer and o-phenylenediamine (o-PD) was used as the chemical functional monomer. • The sensor exhibited higher selectivity than that with one recognition element. • The sensor was successfully applied in actual water and tablet samples. [ABSTRACT FROM AUTHOR]