Canonico-May Stephanie Ann, Beavers Kelsey Ross, Melvin Michael James, Alkilany Alaaldin M, Duvall Craig L, Stone John William
Department of Chemistry, Georgia Southern University, Statesboro, GA 30458, United States.
Department of Materials Science, Vanderbilt University, Nashville, TN 37235, United States.
J Colloid Interface Sci. 2016 Feb 1;463:229-32. doi: 10.1016/j.jcis.2015.10.053. Epub 2015 Oct 23.
Gold nanorods with varying aspect ratios have been utilized in recent years for a wide range of applications including vaccines, surface enhanced Raman spectroscopy (SERS) substrates, and as medicinal therapeutic agents. The surfactant-directed seed mediated approach is an aqueous based protocol that produces monodisperse nanorods with controlled aspect ratios. However, an inherent problem with this approach is poor efficiency of gold conversion from HAuCl4 into nanorods. In fact only ∼15% of gold is converted, motivating the need for alternate synthetic protocols in order to make the process more scalable and efficient as gold nanorods progress toward commercial applications. In the current study, we have significantly improved this conversion by growing rods in several iterations of supernatant solutions that were previously discarded as waste. Inductively coupled plasma mass spectrometry (ICP-MS) data indicates ∼14% gold conversion per nanorod solution with a total recovery of ∼75%. Gold nanorods prepared in consecutive supernatant solutions generally have slightly increased aspect ratios and maintain stability and monodispersity as measured by UV-vis and TEM. The increased nanorod yield minimizes gold waste and results in a greener synthetic approach.
近年来，不同纵横比的金纳米棒已被广泛应用于包括疫苗、表面增强拉曼光谱（SERS）基底以及作为药物治疗剂等众多领域。表面活性剂导向的种子介导法是一种基于水相的方法，可制备出具有可控纵横比的单分散纳米棒。然而，该方法存在一个固有问题，即从氯金酸（HAuCl4）转化为纳米棒的金转化率较低。实际上，只有约15%的金被转化，这促使人们需要寻找替代的合成方案，以便随着金纳米棒向商业应用发展，使该过程更具可扩展性和高效性。在当前的研究中，我们通过在先前作为废物丢弃的上清液溶液中多次生长纳米棒，显著提高了这种转化率。电感耦合等离子体质谱（ICP-MS）数据表明，每个纳米棒溶液的金转化率约为14%，总回收率约为75%。通过连续上清液溶液制备的金纳米棒通常纵横比略有增加，并且通过紫外可见光谱（UV-vis）和透射电子显微镜（TEM）测量显示保持稳定性和单分散性。纳米棒产量的增加最大限度地减少了金的浪费，从而形成了一种更环保的合成方法。
