Graphdiyne nanosheet as a novel sensing platform for self-enhanced electrochemiluminescence of MOF enriched ruthenium (II) in the presence of dual co-reactants for detection of tumor marker.

Graphdiyne (GDY) is a new two-dimensional carbon material with high charge carrier mobility, excellent conductivity, more suitable band gap, and natural pores was introduced as a new electrochemiluminescent sensing platform. Herein, the metal organic framework (MOFs) used for enrichment of luminophore with grafting Ru(bpy)(phen-NH)(Ru-complex) and Ru-complex amine-rich nitrogen-doped carbon nanodots(Ru-NCNDs) via both encapsulating and external decoration and decoration of SmS QDs as coreactant. Then, the MOF enriched Ru-complex (Ru@MOF@NCNDs-Ru@SmS QD) located on a GDY modified ITO electrode developed as a novel and efficient ECL platform. According to the Density Functional Theory (DFT) calculation, the band gap of graphdiyne/Ru(bpy)(phen-NH) system decreased compared to graphdiyne, Ru-complex and also graphene oxide/Ru(bpy)(phen-NH)system, which enhanced (2 folds) the signal response of the presented ECL platform. The ECL response signal of the suggested emitter with high ECL efficiency (13.34%) increased 8 and 4 folds compared to GDY/Ru-NCNDs and GDY/Ru@MOF@NCNDs-Ru as platforms, respectively. The proposed ECL platform applied for CA19-9 antigens detection at concentration range 0.0005 UmL to 200 UmL and detection limit of 0.00013 UmL.The development of GDY based platform for decorating nano luminophores, not only provides the design of ECL luminophores with high performance but also promises the application of the presented strategy for fabrication of ultrasensitive bio affinity sensors as candidates in clinical monitoring and diseases diagnostics.