Synthesis of electrochemiluminescent graphene oxide functionalized with a ruthenium(II) complex and its use in the detection of tripropylamine

We report an approach for the preparation of graphene oxide covalently functionalized with a Ru(II) complex (Ru–GO). A ruthenium(II) complex designed with a long alkyl amino functional group on one of its diimine ligands, bis(2,2′-bipyridine) (N-(2-aminoethyl)-4-(4′-methyl-2,2′-bipyridine-4-yl)butanamide) ruthenium(II), was covalently grafted onto GO by the amide reaction between the amino group of the Ru(II) complex and the carboxyl group of the GO. The as-prepared Ru–GO showed excellent electrochemiluminescence (ECL) activity, good solubility and good stability. Using this hybrid material, a reagent-free ECL method was developed for the detection of tripropylamine to demonstrate the applicability of this new functionalized material. This approach is reliable and highly efficient, and might be extended to other chemiluminescent molecules containing an amino group such as luminol and its analogues to functionalize GO with ECL activity.