LAUSR

Abstract ECL behaviour is highly dependent on electrode surface, materials and dimensions. Therefore, in this work ECL intensity of [Ru(bpy)3]2+/TPrA system was studied with the bare carbon nanofiber screen-printed electrode (CNFs-SPE) and the novel AuNPs/CdTe-QDs/SWCNTs/Chitosan nanocomposite modified CNFs-SPE (CdTe/AuNPs/SWCNTs/Chitosan/CNFs-SPE). ECL intensity was enhanced about 1.0 time with the AuNPs/CdTe-QDs/SWCNTs/Chitosan/CNFs-SPE interface in comparison to the bare CNFs-SPE. Additionally, AuNPs/CdTe-QDs/SWCNTs/Chitosan/CNFs-SPE interface produced ~ 200% increase both in electronic conductivity and in effective surface area in comparison to the bare CNFs-SPE. AuNPs/CdTe-QDs/SWCNTs/Chitosan/CNFs-SPE interface with a combined advantage of high effective surface area, electronic conductivity and ECL intensity was for the first time used to develop an efficient double ECL quenching based immunosensor for the highly sensitive and selective label-free detection of haptoglobin (Hp). Under optimum conditions, the constructed Hp-immunosensor displayed a wide: 100 fg mL−1 to 10 ng mL−1 linear detection range, with a low limit of detection 100 fg mL−1. The calibration plot provides a negative linear relationship between log[c] of Hp and ECL intensity with a coefficient of correlation 0.99. Moreover, this novel biocompatible nanocomposite interface could be used for the ECL based detection of other biomarkers and biomolecules.