A combined experimental-computational approach for electrocatalytic detection of epinephrine using nanocomposite sensor based on polyaniline/nickel oxide

This study reports on a sensor based on nickel oxide nanoparticles (NiO) derived from callistemon viminalis leaf extract and the polymerization of polyaniline (PANI) supported on a glassy carbon electrode (GCE). The novel 2D sensing materials for epinephrine (EP) have been experimentally investigated and theoretically modelled. The electrochemical sensor based on GCE/PANI/NiO exhibits good sensitivity and selectivity for EP. Under optimized conditions, the oxidation peak currents of EP showed a linear dynamic range of 47-354 mu M with limit of detection of 0.05 mu M using square wave voltammetry. The designed sensor demonstrated good practi-cability for the detection of EP in adrenaline injection with good recoveries (102.0 to 105.3%) and precision (RSD of 0.22-2.15%). The Monte Carlo and molecular dynamics simulations were used to assess the active sites of the adsorbate-substrate interface and the computed binding affinities of GCE/PANI/NiO toward EP. The density functional theory calculations confirm the chemical reactivity and stability of EP with HOMO-LUMO energy band gap of -5.48 eV. This opens an insightful and new path to expand the fabrication of novel sensors based on 2D materials using a combined experimental-computational approach.

Automated summary

This study presents a sensor based on nickel oxide nanoparticles and polyaniline that shows good sensitivity and selectivity for the detection of epinephrine. The sensor has been experimentally investigated and theoretically modeled, and its performance has been evaluated in different solutions. Monte Carlo and molecular dynamics simulations were used to assess the binding affinity between the sensor and epinephrine. Density functional theory calculations confirmed the chemical reactivity and stability of the sensor with epinephrine.