Synthesizing gold nanorods (AuNRs) by seed-mediated growth method results in the presence of undesired size and shape particles by-products occupying 10–90% of the population. In this study, AuNRs are synthesized by the seed-mediated growth method using cetyltrimethylammonium bromide (CTAB) as a surfactant. AuNRs with redshifted longitudinal localized surface plasmon resonance (LLSPR) peak, localized in the biological “transparency window” (650–1350 nm), are synthesized after optimizing seed solution, silver nitrate solution, and hydrochloric acid solution volumes, based on the published protocols. A two-step purification method, dialysis followed by centrifugation, is applied to remove excess CTAB and collect LLSPR-redshifted AuNRs with high rod purity (>90%). CTAB is subsequently exchanged with polyethylene glycol (PEG) to improve AuNRs biocompatibility. PEGylated AuNRs are confirmed innocuous to both SN4741 cells and B16F10 cells by the modified MTT assay and the modified lactate dehydrogenase (LDH) assay up to 1 nm and 24 h incubation. In this study, a combined facile synthesis, purification, and surface functionalization approach is proposed to obtain water-dispersible monodispersed AuNRs for drug delivery applications.

中文翻译：

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结合简便的合成、纯化和表面功能化方法可产生用于药物输送应用的单分散金纳米棒

通过种子介导的生长方法合成金纳米棒 (AuNR) 会导致出现不期望的尺寸和形状颗粒副产物，占总体的 10-90%。在这项研究中，使用十六烷基三甲基溴化铵（CTAB）作为表面活性剂，通过种子介导的生长方法合成了AuNRs。根据已发布的方案，在优化种子溶液、硝酸银溶液和盐酸溶液体积后，合成具有红移纵向局域表面等离子共振 (LLSPR) 峰、位于生物“透明窗口”（650–1350 nm）的 AuNR 。采用先透析后离心的两步纯化方法去除多余的 CTAB，并收集高棒纯度 (>90%) 的 LLSPR 红移 AuNR。随后将 CTAB 与聚乙二醇 (PEG) 交换，以提高 AuNR 的生物相容性。通过改良的 MTT 测定和改良的乳酸脱氢酶 (LDH) 测定（长达 1 nm 和 24 小时孵育）证实聚乙二醇化 AuNR 对 SN4741 细胞和 B16F10 细胞无害。在这项研究中，提出了一种简单的合成、纯化和表面功能化相结合的方法，以获得用于药物输送应用的水分散性单分散金纳米棒。