Immobilization of tris(1,10-phenanthroline)ruthenium with graphene oxide for electrochemiluminescent analysis

Electrochemiluminescence (ECL) of ruthenium complexes has broad applications and the immobilization of Ru(bpy)32+ has received extensive attention. In comparison with Ru(bpy)32+, Ru(phen)32+ can be immobilized more easily because of its better adsorbability. In this study, immobilization of Ru(phen)32+ for ECL analysis has been demonstrated for the first time by using graphene oxide (GO) as an immobilization matrix. The immobilization of Ru(phen)32+ is achieved easily by mixing Ru(phen)32+ with GO without using any ion exchange polymer or covalent method. The strong binding of Ru(phen)32+ with GO is attributed to both the π–π stacking interaction and the electrostatic interaction. The Ru(phen)32+/GO modified electrode was characterized by using tripropylamine (TPA) as the coreactant. The linear range of TPA is from 3 × 10−7 to 3 × 10−2 mol L−1 with the detection limit of 3 × 10−7 mol L−1. The ECL sensor demonstrates outstanding long-term stability. After the storage in the ambient environment for 90 days, the ECL response remains comparable with its original signal.

Figure optionsDownload as PowerPoint slideHighlights
► Ru(phen)32+-based regenerable ECL sensor has been demonstrated for the first time.
► Ru(phen)32+ has better adsorbability than Ru(bpy)32+.
► Ru(phen)32+ is readily and strongly immobilized on graphene oxide by adsorption.
► Ru(phen)32+/GO regenerable sensor has excellent long-term stability.
► Ru(phen)32+ is an attractive alternative to Ru(bpy)32+ for regenerable ECL sensors.