Smart electrochemical immunosensor for detection of aspartame in dietary products supported by in silico methods

Aspartame (ASP) is one of the most widely used artificial sweeteners; therefore, there is a need to develop reliable and reproducible analytical methods for its detection. In this study, a novel detection of ASP using biosynthesized polyvinylpyrrolidone-capped silver nanoparticles (PVP-AgNPs) with functionalized multiwalled carbon nanotubes (fMWCNTs) and TIR2 antibodies doped onto glassy carbon electrodes (GCEs) is described. A variety of complementary analytical measurement techniques were employed for the separation and characterization of AgNPs capped with PVP. The electro-oxidation of ASP was noticed by a well-defined oxidation peak potential at 1.4 V. The immunosensor sensor showed a linear dynamic range of 2.89–27.61 μM (R 2 = 0.9170) based on differential pulse voltammetry, with limits of detection and quantification (S/N = 3) of 0.40 and 1.34 μM respectively. The chemical reactivity of ASP was confirmed by density functional theory (DFT) calculations. In addition, a coupled molecular docking and Monte Carlo (MC) simulations revealed a high binding affinity between ASP and the developed GCE/PVP-AgNPs/fMWCNTs/T1R2, electrode. Molecular dynamics (MD) simulations were used to examine the conformational profile of the docked structure. The immunosensor has been applied successfully to sensing of ASP in commercially available dietary products, which can be applied to newly developed electroactive sweeteners. • Successful biogenic synthesis of PVP-AgNPs using Eucalyptus globulus leaf extract .for the design of ASP immunosensor. • Linear dynamic range from 2.89 to 27.61 µM with 0.40 µM detection limits. • Good practicability of the designed sensor (GCE/PVP-AgNPs/fMWCNTs/T1R2) achieved for sensing of ASP in dietary products. • HOMO-LUMO plots obtained from density functional theory calculations revealed the chemically reactivity of ASP. • CV and EIS results correlated with Monte Carlo and molecular dynamics simulations of the modified nanocomposite electrode.