Gold Nanoparticles: Acceptors for Efficient Energy Transfer from the Photoexcited Fluorophores

• 作者: Debanjana Ghosh Nitin Chattopadhyay
• 来源期刊: 光学与光子学期刊(英文)
• 学科: 化学
• 关键词: Gold Nanoparticles TEM SPECTROPHOTOMETRY Fluorescence QUENCHING Energy Transfer PLASMON Absorption Super QUENCHING
• 年，卷（期）: 2013,（1）
• 页码范围: 18-26
• 页数: 9页
• 分类号: O6

摘要

The citrate reduction method of synthesis of gold nanoparticles (AuNP) is standardized with the assistance of instruments like spectrophotometer and TEM. A correlation has been developed between the particle diameter and the fractional concentration of the reductant. This enables one to assess the diameter of the AuNP to be synthesized, in advance, from the composition of the reaction mixture and the diameter of the synthesized particles can be confirmed simply from spectrophotometry. Further, it has been demonstrated that the synthesized AuNPs serve as excellent acceptors for a super-efficient energy transfer (ET) from the donor coumarin 153, leading to a quenching of fluorescence of the latter. The Stern-Volmer constants determined from the fluorescence lifetimes are in the range 107 - 109 mol-1·dm3 and are orders of magnitude higher than the normal photochemical quenching processes. The energy transfer efficiency increases radically with an increase in the size of the metal nanoparticle. The highly efficient energy transfer and the variation of the efficiency of the ET process with a variation of the particle size is ascribed to a large enhancement in the extinction coefficient and an increase in the spectral overlap between the plasmon absorption band of AuNPs and the fluorescence spectrum of C153 with an increase in the size of the nanoparticles. The impact of the work remains in providing a demonstration of a super quenching effect of the AuNPs and projects that they can be exploited for developing biosensors with high degree of sensitivity, if tagged to the biomacromolecules.