Laboratorio de polímeros (POLIUNA), School of Chemistry, Universidad Nacional, Heredia 86-3000, Costa Rica.
State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, P. R. China.
Langmuir. 2021 Mar 23;37(11):3446-3455. doi: 10.1021/acs.langmuir.1c00104. Epub 2021 Mar 8.
Negatively charged liposomes accomplished both functions as a reducing and stabilizing agent in the synthesis of gold nanotriangles (GNTs). Liposomes are based on a mixture of phospholipids phosphatidylcholine/phosphoglycerol, and they were used as a template phase to perform the GNTs. The method was evaluated under different conditions such as temperature, reaction time, phosphoglycerol chain length, and precursor concentration. Isotropic and anisotropic gold nanoparticles are formed simultaneously during the synthesis. Therefore, by combining centrifugation and depletion flocculation strategies, the sample was concentrated in terms of GNTs from 15% crude to 80% by using sodium dodecyl sulfate (SDS). As a result, a green colored dispersion was obtained containing highly purified, well-defined, negatively charged GNTs, where the edge length of most particles is centered in the range of 60-80 nm with an average thickness of 7.8 ± 0.1 nm. By this purification process, it was possible to highly increase the yield in terms of GNTs. Other surfactants [cetyltrimethylammonium chloride (CTAC), hexadecyltrimethylammonium bromide (CTAB), Tween 20, and dodecyldimethylammonium bromide] were evaluated during the purification stage, and both CTAB and CTAC show similar results to those obtained by using SDS. These GNTs are potential candidates for future applications in molecular imaging, photothermal therapy, drug delivery, biosensing, and photodynamic therapy.
带负电荷的脂质体在金纳米三角体（GNTs）的合成中既起到了还原剂的作用，又起到了稳定剂的作用。脂质体基于磷脂酰胆碱/磷酸甘油的混合物，它们被用作模板相来进行 GNTs 的制备。该方法在不同条件下进行了评估，如温度、反应时间、磷酸甘油链长和前体浓度。在合成过程中同时形成各向同性和各向异性的金纳米粒子。因此，通过结合离心和耗尽絮凝策略，使用十二烷基硫酸钠（SDS）将样品从 15%粗产物浓缩到 80%的 GNTs。结果，得到了一种绿色的分散体，其中含有高度纯化、定义明确、带负电荷的 GNTs，大多数颗粒的边长集中在 60-80nm 范围内，平均厚度为 7.8±0.1nm。通过这种纯化过程，可以大大提高 GNTs 的产量。在纯化阶段还评估了其他表面活性剂[十六烷基三甲基氯化铵（CTAC）、十六烷基三甲基溴化铵（CTAB）、吐温 20 和十二烷基二甲基溴化铵]，CTAB 和 CTAC 的结果与使用 SDS 时相似。这些 GNTs 是未来在分子成像、光热治疗、药物传递、生物传感和光动力治疗等领域应用的潜在候选者。
