Plasmon-Enhanced Electrochemiluminescence at the Single-Nanoparticle Level

Plasmon-enhanced electrochemiluminescence (ECL) at the single-nanoparticle (NP) level was investigated by ECL microscopy. The Au NPs were assembled into an ordered array, providing a high-throughput platform that can easily locate each NP in sequential characterizations. A strong dependence of ECL intensity on Au NP configurations was observed. We demonstrate for the first time that at the single-particle level, the ECL of Ru(bpy)(3)(2+)-TPrA was majorly quenched by small Au NPs (<40nm), while enhanced by large Au ones (>80nm) due to the localized surface plasmon resonance (LSPR). Notably, the ECL intensity was further increased by the coupling effect of neighboring Au NPs. Finite Difference Time Domain (FDTD) simulations conformed well with the experimental results. This plasmon enhanced ECL microscopy for arrayed single NPs provides a reliable tool for screening electrocatalytic activity at a single particle.

Automated summary

Plasmon-enhanced electrochemiluminescence (ECL) at the single-nanoparticle (NP) level was investigated using ECL microscopy. An ordered array of gold nanoparticles (Au NPs) was used, allowing for high-throughput characterization and a strong dependence of ECL intensity on Au NP configurations was observed. It was demonstrated that small Au NPs (<40nm) quenched the ECL of Ru(bpy)(3)(2+)-TPrA, while large Au NPs (>80nm) enhanced it due to localized surface plasmon resonance (LSPR). The coupling effect of neighboring Au NPs further increased the ECL intensity. The results were supported by Finite Difference Time Domain (FDTD) simulations. This plasmon-enhanced ECL microscopy provides a reliable tool for screening electrocatalytic activity at the single-particle level.