Center for Nanospace-confined Chemical Reactions (NCCR), Pohang University of Science and Technology (POSTECH), Pohang, 37673, South Korea.
Department of Chemistry, Pohang University of Science and Technology (POSTECH), Pohang, 37673, South Korea.
Small. 2023 Aug;19(35):e2301190. doi: 10.1002/smll.202301190. Epub 2023 Apr 25.
Silicon nanostructures (SiNSs) can provide multifaceted bioapplications; but preserving their subhundred nm size during high-temperature silica-to-silicon conversion is the major bottleneck. The SC-SSR utilizes an interior metal-silicide stratum space at a predetermined radial distance inside silica nanosphere to guide the magnesiothermic reduction reaction (MTR)-mediated synthesis of hollow and porous SiNSs. In depth mechanistic study explores solid-to-hollow transformation encompassing predefined radial boundary through the participation of metal-silicide species directing the in-situ formed Si-phase accumulation within the narrow stratum. Evolving thin-porous Si-shell remains well protected by the in-situ segregated MgO emerging as a protective cast against the heat-induced deformation and interparticle sintering. Retrieved hydrophilic SiNSs (<100 nm) can be conveniently processed in different biomedia as colloidal solutions and endocytosized inside cells as photoluminescence (PL)-based bioimaging probes. Inside the cell, rattle-like SiNSs encapsulated with Pd nanocrystals can function as biorthogonal nanoreactors to catalyze intracellular synthesis of probe molecules through C-C cross coupling reaction.
硅纳米结构（SiNSs）可以提供多方面的生物应用；但在高温二氧化硅到硅的转化过程中保持其亚百纳米的尺寸是主要的瓶颈。SC-SSR 利用二氧化硅纳米球内预定的径向距离内的内部金属硅化物层空间来引导镁热还原反应（MTR）介导的空心和多孔 SiNSs 的合成。深入的机制研究通过参与金属硅化物物种的参与，探索了包括预定的径向边界的固-空转变，该物种指导原位形成的 Si 相在狭窄层内的积累。不断演变的薄多孔 Si 壳通过原位分离出的 MgO 得到很好的保护，MgO 作为一种保护性铸型，防止了热诱导变形和颗粒间烧结。回收的亲水性 SiNSs（<100nm）可以方便地在不同的生物介质中作为胶体溶液进行处理，并作为基于光致发光（PL）的生物成像探针被细胞内吞。在细胞内，封装有 Pd 纳米晶的摇铃状 SiNSs 可以作为双正交纳米反应器，通过 C-C 交叉偶联反应来催化细胞内探针分子的合成。
