Highly Sensitive Emission Sensor Based on Surface Plasmon Enhanced Energy Transfer between Gold Nanoclusters and Silver Nanoparticles

In the study of interaction between emissive gold nanoclusters and silver nanoparticles, we explored that the emission of gold nanoclusters is very sensitive to the presence of silver nanoparticles. Quite remarkably, the quenching ratio can reach more than several hundred times. We demonstrate that the underlying mechanism can be attributed to the Surface energy transfer with the quenching efficiency following the expression chi = 1/[1 + (d/d(0))(4)], where d is the distance between gold nanoclusters and silver nanoparticles, and d(0) is the characteristic length of energy transfer. This highly sensitive behavior in the composite consisting of relatively nontoxic gold nanoclusters and silver nanoparticles may find a powerful potential in developing biomedical applications, Such as biosensors and drugs delivery.