Atom Absorption Energy Directed Symmetry‐Breaking Synthesis of Au–Ag Hierarchical Nanostructures and Their Efficient Photothermal Conversion

Abstract

Asymmetric plasmonic hierarchical nanostructures (HNs) are of great significance in optics, catalysis, and sensors, but the complex growth kinetics and lack of fine structure design limit their practical applications. Herein, a new atom absorption energy strategy is developed to achieve a series of Au–Ag HNs with the continuously tuned contact area in Janus and Ag island number/size on Au seeds. Different from the traditional passive growth mode, this strategy endows seed with a hand to capture the hetero atoms in a proactive manner, which is beyond the size, shape, and assembles of Au seed. Density functional theory reveals ththe adsorption of PDDA on Au surface leads to lower formation energy of Au–Ag bonds (−3.96 eV) than FSDNA modified Au surface (−2.44 eV). The competitive adsorption of two ligands on Au seed is the decisive factor for the formation of diverse Au–Ag HNs. In particular, the Au–Ag2 HNs exhibit outstanding photothermal conversion capability in the near‐infrared window, and in vivo experiments verify them as superior photothermal therapy agents. This work highlights the importance of the atom absorption energy strategy in unlocking the diversity of HNs and may push the synthesis and application of superstructures to a higher level.

Rapid controllable synthesis of branched Au superparticles: formation mechanism of toggling the growth mode and their applications in optical broadband absorption

“…Usually, there are two main types of seed-mediated growth modes of nanoparticles, one is the Frank-van der Merwe (FM) growth mode, a layer by layer growth mode; the other is the Volmer-Weber (VW) growth mode, an island on surface growth mode. 13,[19][20][21] The decisive factor for the growth mode is the surface energy at the Please do not adjust margins Please do not adjust margins growth interface in these two modes. Generally, the surface energy of FM mode is relatively low, conversely, a higher surface energy is a prerequisite for island growth in VW mode.…”

Advances in the Application of Photothermal Composite Scaffolds for Osteosarcoma Ablation and Bone Regeneration

“…), which are less expensive than noble metals, less cytotoxic, and easier to fabricate, are typically represented by Cu 2– x S and Fe 3 O 4 . The energy band jump of copper ions (Cu 2+ ) in Cu 2– x S imparts its light absorption properties. , In addition, the photothermal conversion efficiency can be effectively improved by adjusting the shape and size of copper-based nanomaterials. , Fe 3 O 4 has a photothermal effect due to the nonradiative motion of electrons between its different defect sites. As a magnetic nanomaterial, it is capable of enhancing the photothermal effect with the help of a mild alternating magnetic field .…”

Exclusive Core-Janus Satellite Assembly Based on Au–Ag Janus Self-Aligned Distributions with Abundant Hotspots for Ultrasensitive Detection of CA19-9

“…The Janus structure integrates different functions of two domains of Au and Ag and possesses unique optical properties due to the asymmetric structure and strong plasmon coupling. The structure can generate significantly enhanced SERS signals as a result of the formation of high-intensity hotspots in the neck region between the Au and Ag domain. − Furthermore, subtle changes in the bimetallic neck region greatly affect the generated electromagnetic field and optical signals, allowing for effective tuning of the SERS performance by varying the degree of narrowness and sharpness of the neck junction . The Janus structures have been acknowledged as excellent platforms for highly sensitive and quantifiable SERS applications. − The configuration of the core–satellite structure is enriched by employing Au–Ag Janus satellites, endowing the structure with a greater degree of tunability of optical properties.…”