Anisotropic gold nanoparticles displaying plasmon band in the near infrared region can play a crucial role in cancer therapy particularly with techniques such as photothermal therapy (PTT) and photodynamic therapy (PDT). Herein, we report an efficient, sustainable, one pot protocol for the fabrication of an unusual gold anisotropic shape, which we have named as twisted gold nanorods. These particles, though having dimensions in the nanoscale regime comparable to those of gold nanorods, display a continuous flat plasmon band like that of 2-D gold nanowire networks, extended up to the NIR-III (SWIR) range. The proposed strategy is simple and does not require any seed mediation, heating or potential toxic templates or organic solvents. Our process is based on the slow reduction of gold salt in presence of two mild reducing agents viz. l-tyrosine (an amino-acid) and trisodium citrate. We observed that when both molecules are present together in particular concentrations, they direct the growth in form of twisted gold nanorods. The mechanism of growth has been described by a Diffusion Limited Aggregation numerical scheme, where it was assumed that both L-tyrosine and the gold ions in solution undergo a stochastic Brownian motion. The predictions of the model matched with the experiments with a good accuracy, indicating that the initial hypothesis is correct. The final structure has been thoroughly characterized in terms of morphology, while SERS and cytotoxic activity have also been demonstrated.

在近红外区域显示等离激元能带的各向异性金纳米粒子在癌症治疗中起着至关重要的作用，尤其是利用光热疗法（PTT）和光动力疗法（PDT）等技术。在此，我们报告了一种有效，可持续的单罐协议，用于制造不寻常的金各向异性形状，我们将其称为扭曲金纳米棒。这些颗粒尽管在纳米尺度上具有与金纳米棒相当的尺寸，但仍显示出连续的平坦等离激元带，就像2-D金纳米线网络一样，延伸到NIR-III（SWIR）范围。提出的策略很简单，不需要任何种子调解，加热或潜在的有毒模板或有机溶剂。我们的过程基于在两种温和的还原剂存在下缓慢还原金盐的过程即。1-酪氨酸（一种氨基酸）和柠檬酸三钠。我们观察到，当两​​个分子以特定的浓度一起存在时，它们以扭曲的金纳米棒的形式引导生长。生长的机制已通过扩散有限聚集数值方案进行了描述，其中假定溶液中的L-酪氨酸和金离子都经历了随机的布朗运动。该模型的预测结果与实验结果吻合良好，表明初始假设是正确的。最终结构已在形态方面进行了充分表征，同时还证明了SERS和细胞毒性活性。