Electrochemiluminescence study of AuNPs/CdTe-QDs/SWCNTs/chitosan nanocomposite modified carbon nanofiber screen-printed electrode with [Ru(bpy)3]2+/TPrA

Abstract

Generation of ECL by a set of luminophore-corectant system is highly dependent on the concentration of the luminophore, coreactant; applied photomultiplier tube (PMT) voltage; materials, dimensions and the surface area of the electrode. Therefore, in this work firstly concentration of the luminophore ([Ru(bpy)3]2+), coreactant (TPrA); applied voltage on PMT was optimised for the high ECL intensity with the carbon nanofiber screen-printed electrode (CNFs-SPE). Secondly, with the optimised concentration of the [Ru(bpy)3]2+, TPrA and optimised applied PMT voltage; ECL intensity of the bare poly(3,4-ethylenedioxythiophene) screen-printed electrode (PEDOT-SPE), carbon screen-printed electrode (C-SPE) and CNFs-SPE was compared. Study demonstrated that the ECL generated on the surface of the PEDOT-SPE, C-SPE and CNFs-SPE was 1214 (a.u.), 3779 (a.u.), and 6346 (a.u.) respectively. Thirdly, bare CNFs-SPE was modified with Chitosan, and nanocomposite of: SWCNTs/Chitosan, CdTe-QDs/Chitosan, AuNPs/Chitosan, CdTe-QDs/SWCNTs/Chitosan, AuNPs/SWCNTs/Chitosan, CdTe-QDs/AuNPs/Chitosan, and AuNPs/CdTe-QDs/SWCNTs/Chitosan; and their ECL was compared. This study illustrated that AuNPs/CdTe-QDs/SWCNTs/Chitosan-nanocomposite modified CNFs-SPE (AuNPs/CdTe-QDs/SWCNTs/Chitosan/CNFs-SPE) displayed highest ECL (10,452 a.u.), and ~ 200% more as compare to the bare CNFs-SPE. Further, AuNPs/CdTe-QDs/SWCNTs/Chitosan/CNFs-SPE displayed ~ 200% increase in effective surface area and electronic conductivity in comparison to the bare CNFs-SPE. In the fourth and last study, ECL stability of the AuNPs/CdTe-QDs/SWCNTs/Chitosan-nanocomposite for continuous 10 cycles was studied, which showed that AuNPs/CdTe-QDs/SWCNTs/Chitosan/CNFs-SPE was highly stable with only ~ 10% decrease in ECL intensity.