Structural parameters play a crucial role in determining the electromagnetic and thermal responses of gold nanoconstructs (GNCs) at near-infrared (NIR) wavelengths. Therefore, developing GNCs for reliable, high-contrast photoacoustic imaging has been focused on adjusting structural parameters to achieve robust NIR light absorption with photostability. In this study, we introduce an efficient photoacoustic imaging contrast agent: gold sphere chains (GSCs) consisting of plasmonically coupled gold nanospheres. The chain geometry results in enhanced photoacoustic signal generation originating from outstanding photothermal characteristics compared to traditional gold contrast agents, such as gold nanorods. Furthermore, the GSCs produce consistent photoacoustic signals at laser fluences within the limits set by the American National Standards Institute. The exceptional photoacoustic response of GSCs allows for high-contrast photoacoustic imaging over multiple imaging sessions. Finally, we demonstrate the utility of our GSCs for molecular photoacoustic cancer imaging, both in vitro and in vivo, through the integration of a tumor-targeting moiety.

中文翻译：

---

将金纳米球耦合到纳米链结构中以实现高对比度纵向光声成像

结构参数在确定金纳米结构 (GNC) 在近红外 (NIR) 波长下的电磁和热响应方面发挥着至关重要的作用。因此，开发用于可靠、高对比度光声成像的 GNC 一直致力于调整结构参数，以实现强大的近红外光吸收和光稳定性。在这项研究中，我们引入了一种高效的光声成像造影剂：由等离子体耦合的金纳米球组成的金球链（GSC）。与传统的金造影剂（例如金纳米棒）相比，链几何形状可增强光声信号的产生，这是由于其出色的光热特性。此外，GSC 在美国国家标准协会设定的限制范围内的激光能量密度下产生一致的光声信号。 GSC 卓越的光声响应允许在多个成像过程中进行高对比度光声成像。最后，我们通过整合肿瘤靶向部分，展示了 GSC 在体外和体内分子光声癌症成像中的实用性。