INVESTIGATIONS INTO THE UPTAKE, FORMATION, AND EXTRACTION OF GOLD NANOPARTICLES

该子项目是利用NIH/NCRR资助的中心赠款提供的资源的许多研究子项目之一。子项目和研究者（PI）可能从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。所列机构为中心，不一定是研究者所在机构。我们已经显示了使用苜蓿和Chilopsis linearis的活植物的金的吸收，这导致金纳米颗粒的形成。此外，我们还显示了在苜蓿、燕麦、小麦和啤酒花的失活组织上形成金纳米颗粒。然而，最近我们一直在研究从活的和灭活的生物材料中提取金纳米粒子。我们已经看到使用CTAB季铵离子的一些成功。金纳米颗粒的提取受到纳米颗粒稳定性问题的困扰，XAS提供了一种通过比较从我们将使用的提取程序获得的XANES和EXAFS结果来跟踪金纳米颗粒稳定性的极好方法。此外，我们一直在研究使用金螯合剂来增加活植物对金的吸收的方法。然而，这些化学物质对金纳米颗粒形成的影响尚未深入研究。我们已经从XAS研究的初步结果中看到，活植物中的金的化学成分取决于所使用的化学螯合剂。在存在硫氰酸盐的情况下将金引入生长培养基中导致在活植物内产生金纳米颗粒。但是，硫脲的使用导致了化合物的混合物，表明存在含金-硫化合物和金纳米颗粒，这需要进一步研究以了解植物中与金配位的化合物。此外，我们目前正在测试从活植物组织中提取金纳米颗粒的化合物和消化方案，XAS将成为这些研究的宝贵工具。XAS将为我们提供从活的和灭活的生物组织中提取过程中金纳米颗粒稳定性的重要信息。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. We have shown the uptake of gold using live plants of alfalfa and Chilopsis linearis which results in the formation of gold nanoparticles. In addition, we have also shown the formation of gold nanoparticles on inactivated tissues of alfalfa, oat, wheat, and hops. However, more recently we have been investigating the extraction of gold nanoparticles from both the living and inactivated biological materials. We have seen some success using CTAB a quaternary ammonium ion. The extraction of gold nanoparticles is plagued by questions of nanoparticle stability and XAS provides an excellent method to follow the stability of gold nanoparticles by comparison of the XANES and EXAFS results obtained from the extraction procedures that we will be using. In addition, we have been investigating methods to increase gold uptake by live plants using gold chelating agents. Yet, the effects of these chemicals on the formation of the gold nanoparticles have not been studied in depth. We have seen from preliminary results from XAS studies the chemistry of the gold within the live plants is dependent on the chemical chelating agent used. Gold introduced in the growth media in the presence of thiocyanate resulted in the production of gold nanoparticles within the live plant. But, the use of thiourea resulted in a mixture of compounds indicating the presence of both gold-sulfur containing compounds and gold nanoparticles, this needs to be investigated further to understand the compounds coordinating the gold within the plants. In addition, we are currently testing compounds and digestion protocols for the extraction of gold nanoparticles from the living plant tissues, which XAS will be an invaluable tool for these studies. XAS will provide us with important information on the stability of gold nanoparticles during the extraction process from both live and inactivated biological tiss