Non-enzymatic glucose electrochemical sensor based on silver nanoparticle decorated organic functionalized multiwall carbon nanotubes

Abstract

An efficient, fast and stable non-enzymatic glucose sensor was prepared by decorating silver nanoparticles on organic functionalized multiwall carbon nanotubes (AgNPs/F-MWCNTs). MWCNTs were functionalized with organic amine chains and characterized using energy-dispersive X-ray and FT-IR spectroscopy. Moreover, the decorated AgNPs monitored using transmission electron microscopy showed spherical shapes with a mean size of 9.0 ± 2.8 nm. For further study, a glassy carbon electrode (GCE) was modified using the synthesized composite and evaluation of the modification was conducted using cyclic voltammetry and electrochemical impedance spectroscopy. The electrochemical data revealed that modification of the GCE leads to easier electron transfer compared to the bare unmodified GCE due to the presence of the functionalized MWCNTs accompanied with the electrocatalytic effect of the decorated silver nanoparticles. Furthermore, the fabricated modified electrode was applied as a non-enzymatic glucose sensor using electrochemical techniques including cyclic voltammetry and hydrodynamic chronoamperometry. The results obtained from the amperometric analysis of glucose in a 0.1 M NaOH solution indicated an efficient performance of the electrode with a low detection limit of 0.03 μM and a high sensitivity of 1057.3 μA mM⁻¹, as well as a linear dynamic range of 1.3 to 1000 μM. A practical application of this sensor was also examined by analyzing glucose in the presence of common interfering species that exist in a real sample of human blood serum.