Tunable growth of a single high-density ZIF nanoshell on a gold nanoparticle isolated in an optical trap
Tunable growth of a single high-density ZIF nanoshell on a gold nanoparticle isolated in an optical trap
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DOI：
10.1039/d3nr05316d
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发表时间：
2024-01-09
期刊：
影响因子：
6.7
通讯作者：
Kamenetska，Maria
中科院分区：
文献类型：
--
作者：
Jackson，Daniel;Rose，Maitreya;Kamenetska，Maria
在这里，我们展示了一种使用光镊在金纳米颗粒（AuNPs）表面可控生长高质量的沸石咪唑盐框架（ZIF）纳米壳的全光学方法，并通过暗场光谱监测其生长。我们的单粒子方法允许我们在光学显微镜的焦点处将单个NP定位在包含ZIF前体的显微镜载玻片腔内，并通过局部加热启动生长，而不会影响整体系统。暗场光谱用于表征随着ZIF晶体在表面生长而引起的折射率变化对AuNP局部表面等离子体共振（LSPR）的变化。我们证明该过程可以推广到生长各种类型的ZIF晶体，如ZIF-8， ZIF-11和以前未记载的ZIF品种。利用计算模型和实验方法，我们确定了ZIF层的厚度自限制在~ 50nm或更小，这取决于捕获激光功率。关键的是，这里发现的壳的折射率高于1.6，表明高密度晶体的形成，以前只能通过缓慢的原子层沉积而不是通过大量加热过程来实现。这里开发的单粒子方法为自底向上可控生长具有可调光学特性的定制纳米结构打开了大门。
Here, we demonstrate an all-optical method using an optical tweezer to controllably grow high quality zeolitic imidazolate framework (ZIF) nanoshells on the surface of gold nanoparticles (AuNPs) and monitor the growth via darkfield spectroscopy. Our single particle approach allows us to localize an individual NP within a microscope slide chamber containing ZIF precursors at the focus of an optical microscope and initiate growth through localized heating without affecting the bulk system. Darkfield spectroscopy is used to characterize changes to the localized surface plasmon resonance (LSPR) of the AuNP resulting from refractive index changes as the ZIF crystal grows on the surface. We show that the procedure can be generalized to grow various types of ZIF crystals, such as ZIF-8, ZIF-11, and a previously undocumented ZIF variety. Utilizing both computational models and experimental methods, we identify the thickness of ZIF layers to be self-limiting to ∼50 nm or less, depending on the trapping laser power. Critically, the refractive index of the shells here was found to be above 1.6, indicating the formation of high-density crystals, previously accessible only through slow atomic layer deposition and not through a bulk heating process. The single particle method developed here opens the door for bottom-up controllable growth of custom nanostructures with tunable optical properties.