Department of Chemistry, York University, 4700 Keele Street Toronto, Ontario, M3J 1P3, Canada.
Department of Chemistry and Biochemistry, Wilfrid Laurier University, 75 University Ave. W., Waterloo, Ontario N2L 3C5, Canada.
Analyst. 2021 Dec 20;147(1):155-164. doi: 10.1039/d1an01421h.
We present core-satellite assemblies comprising a solid gold nanoparticle as the core and hollow decahedral gold nanoshells as satellites for tuning the optical properties of the plasmonic structure for sensing. The core-satellite assemblies were fabricated on a substrate the layer-by-layer assembly of nanoparticles linked by DNA. We used finite-difference time-domain simulations to help guide the geometrical design, and characterized the optical properties and morphology of the solid-shell nanoparticle assemblies using darkfield microscopy, single-nanostructure spectroscopy, and scanning electron microscopy. Plasmon coupling yielded resonant peaks at longer wavelengths in the red to near-infrared range for solid-shell assemblies compared with solid-solid nanoparticle assemblies. We examined sensing with the solid-shell assemblies using adenosine triphosphate (ATP) as a model target and ATP-aptamer as the linker. Binding of ATP induced disassembly and led to a decrease in the scattering intensity and a color change from red to green. The new morphology of the core-satellite assembly enabled plasmonic color-coding of multiplexed sensors. We demonstrate this potential by fabricating two types of assemblies using DNA linkers that target different molecules - ATP and a model nucleic acid. Our work expands the capability of chip-based plasmonic nanoparticle assemblies for the analysis of multiple, different types of biomolecules in small sample sizes including the microenvironment and single cells.
我们提出了一种包含实心金纳米颗粒作为核心和空心十面体金纳米壳作为卫星的核-壳组装体，用于调整等离子体结构的光学性质以进行感测。该核-壳组装体是在基板上通过 DNA 连接的纳米颗粒逐层组装而成的。我们使用有限差分时域模拟来帮助指导几何设计，并使用暗场显微镜、单纳米结构光谱学和扫描电子显微镜来表征实心壳纳米颗粒组装体的光学性质和形态。与实心-实心纳米颗粒组装体相比，等离子体耦合在较长的波长下在红色到近红外范围内产生了共振峰。我们使用三磷酸腺苷 (ATP) 作为模型靶标和 ATP-适体作为连接物来检查实心壳组装体的感测。ATP 的结合诱导了组装体的解体，导致散射强度降低和颜色从红色变为绿色。核-壳组装体的新形态实现了多重传感器的等离子体颜色编码。我们通过使用针对不同分子（ATP 和模型核酸）的 DNA 接头制造两种类型的组装体来证明了这种潜力。我们的工作扩展了基于芯片的等离子体纳米颗粒组装体在分析小样本量（包括微环境和单细胞）中的多种不同类型生物分子的能力。
