Yuan Peiyan, Ma Rizhao, Gao Nengyue, Garai Monalisa, Xu Qing-Hua
Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543.
Nanoscale. 2015 Jun 14;7(22):10233-9. doi: 10.1039/c5nr01409c. Epub 2015 May 20.
Au and Ag nanoparticles (NPs) have been known to display significantly enhanced two-photon photoluminescence (2PPL) upon the formation of nanoparticle aggregates. The enhancement effect of the core-shell nanoparticles has not been explored so far. Here we have prepared Au@Ag bimetallic core-shell nanoparticles with different thicknesses (1.1, 2.1, 3.5, 4.5, and 5.5 nm) of silver coating on 19 nm Au NPs to investigate the composition effects on plasmon coupling-enhanced 2PPL. A maximum 2PPL enhancement factor (IcoupledNPs/IisolatedNPs) of up to 840-fold was obtained for Au@Ag NPs with ∼3.5 nm Ag nanoshells. These Au@Ag NPs were subsequently utilized in two-photon detection of S1 nuclease as a photoluminescence turn on probe. This method displayed high sensitivity with the limit of detection of 1.4 × 10(-6) U μL(-1) and an excellent selectivity.
已知金纳米颗粒（NPs）和银纳米颗粒在形成纳米颗粒聚集体时会表现出显著增强的双光子光致发光（2PPL）。迄今为止，核壳纳米颗粒的增强效果尚未得到研究。在这里，我们制备了在19nm金纳米颗粒上具有不同银涂层厚度（1.1、2.1、3.5、4.5和5.5nm）的Au@Ag双金属核壳纳米颗粒，以研究组成对等离子体耦合增强2PPL的影响。对于具有约3.5nm银纳米壳的Au@Ag纳米颗粒，获得了高达840倍的最大2PPL增强因子（I耦合纳米颗粒/I孤立纳米颗粒）。这些Au@Ag纳米颗粒随后被用作S1核酸酶的双光子检测中的光致发光开启探针。该方法显示出高灵敏度，检测限为1.4×10（-6）U μL（-1），并且具有出色的选择性。
