Ji Jin, Wang Junsheng, Jiang Tingting, Chen Zijie, Wang Zhiwei, Feng Yuhua
Institute of Advanced Synthesis (IAS), School of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing 211816, China.
Inorg Chem. 2024 Jul 29;63(30):14256-14265. doi: 10.1021/acs.inorgchem.4c02482. Epub 2024 Jul 16.
Utilizing the strong ligand control effects of l-cysteine (l-Cys), the growth of Au on Au triangular nanoplate (AuTN) seeds was continuously tuned from layer-by-layer (the Frank-van der Merwe) to layer-plus-island (the Stranski-Krastanov), and island (the Volmer-Weber) growth modes, leading to the formation of a series of Au-on-AuTN heterostructures. Within the window of VW growth mode (featured by the growth of Au spikes and branches on AuTNs), the effective localized surface plasmon resonance (LSPR) coupling led to the selective strengthening of the "valley" absorptions, leading to smooth and flat absorption curves. Interestingly, through engineering the number/density, size, and branching degree of the Au branches, except for the black color, full spectrum absorption within 400-1300 nm wavelength was achieved on Au-branch-on-AuTN structures. Mechanistic studies revealed that the blackbody absorption property of the Au-branch-on-AuTN originates from the well-balanced intraparticle LSPR couplings among the neighboring Au branches. The tunable blackness and the full spectrum absorption property made the Au-branch-on-AuTN heterostructure a suitable candidate for various plasmonic-related applications, such as a wide spectrum light absorber, photoacoustic imaging contrast agent, and photothermal therapy medium. In addition, our strong ligand control in Au-branch-on-AuTN heterostructures could be extended to other hybrid systems with diverse material combinations, so long as to find the proper strong ligand.
利用 l-半胱氨酸（l-Cys）的强配体控制效应，依次将金（Au）在金三角纳米片（AuTN）种子上的生长模式从逐层生长（弗兰克-范德梅尔生长模式）调整为层加岛状生长（斯特兰斯基-克拉斯坦诺夫生长模式）以及岛状生长（伏尔默-韦伯生长模式），进而形成了一系列 Au-on-AuTN 异质结构。在伏尔默-韦伯生长模式窗口内（其特征为 AuTN 上生长出金尖峰和分支），有效的局域表面等离子体共振（LSPR）耦合导致“谷”吸收选择性增强，从而得到平滑且平坦的吸收曲线。有趣的是，通过调控金分支的数量/密度、尺寸和分支程度，除了黑色之外，在 Au-branch-on-AuTN 结构上实现了 400 - 1300 nm 波长范围内的全光谱吸收。机理研究表明，Au-branch-on-AuTN 的黑体吸收特性源于相邻金分支之间颗粒内 LSPR 耦合的良好平衡。这种可调控的黑色度和全光谱吸收特性使得 Au-branch-on-AuTN 异质结构成为各种等离子体相关应用的合适候选材料，例如宽光谱光吸收器、光声成像造影剂和光热治疗介质。此外，我们在 Au-branch-on-AuTN 异质结构中的强配体控制可扩展到其他具有不同材料组合的混合体系，只要找到合适的强配体即可。
