Measuring nanoparticle-induced resonance energy transfer effect by electrogenerated chemiluminescent reactions

Electrogenerated chemiluminescence (ECL) efficiencies, redox potentials, photoluminescent (PL) (quenching and coupling) effects, and AFM images for the [Ru(bpy)(3)](2+)/Au@tiopronin system were determined in aqueous solutions of the gold nanoparticles (NPs) at pH 7.0. The most remarkable finding was that ECL measurements can display the nanoparticle-induced resonance energy transfer (NP-RET) effect. Its effectiveness was quantified through a coefficient, K((NP-RET)(ECL)), which measures how much an ECL reaction has been enhanced. Moreover, the NP-RET effect was also checked using PL measurements, in such a way that a coefficient, K((NP-RET)(PL)), was determined; both constants, K((NP-RET)(ECL)) and K((NP-RET)(PL)) being in close agreement. It is important to highlight the fact that the NP-RET effect is only displayed in diluted solutions in which there is no NPs self-aggregation. The existence of the NPs self-aggregation behavior is revealed through AFM measurements.