Sharma Varsha, Sundaramurthy Anandhakumar
SRM Research Institute, Department of Biomedical Engineering, and Department of Physics and Nanotechnology, SRM Institute of Science and Technology, Kattankulathur, Kancheepuram, Tamil Nadu 603203, India.
ACS Omega. 2019 Jan 9;4(1):628-636. doi: 10.1021/acsomega.8b02820. eCollection 2019 Jan 31.
We report a methodology to encapsulate gold nanorods (AuNRs) and gold bipyramids (AuBPs) into polyelectrolyte capsules for catalytic application. Microreactors (capsules with encapsulated NRs or BPs) were fabricated by sequential deposition of poly(allylamine hydrochloride) and dextran sulfate on modified sacrificial template, followed by core dissolution. AuNRs and AuBPs of size 25-30 nm were successfully encapsulated in the fabricated polyelectrolyte capsules and were stable and distributed uniformly in the interior. Fabricated microreactors were investigated as catalysts for the reduction of -nitrophenol to -aminophenol in the presence of sodium borohydride in aqueous phase. Reaction parameters such as order, conversion, and rate constants were estimated for microreactors and compared to free anisotropic nanoparticles in suspension. The reaction rate was higher for NRs in both free and capsule forms compared to BPs. Microreactors demonstrated excellent catalytic activity even after three times of use. Such capsules have high potential for use as microreactors in applications such as catalysis, drug delivery, imaging, and cancer chemo-photothermal therapy.
我们报道了一种将金纳米棒（AuNRs）和金双锥体（AuBPs）封装到聚电解质胶囊中用于催化应用的方法。微反应器（封装有NRs或BPs的胶囊）是通过在改性牺牲模板上依次沉积聚（烯丙胺盐酸盐）和硫酸葡聚糖，然后进行核溶解来制备的。尺寸为25 - 30 nm的AuNRs和AuBPs成功封装在制备的聚电解质胶囊中，并且在内部稳定且均匀分布。所制备的微反应器被研究作为在水相中硼氢化钠存在下将对硝基苯酚还原为对氨基苯酚的催化剂。估计了微反应器的反应参数，如反应级数、转化率和速率常数，并与悬浮液中的游离各向异性纳米颗粒进行了比较。与BPs相比，游离形式和胶囊形式的NRs的反应速率都更高。微反应器即使在使用三次后仍表现出优异的催化活性。这种胶囊在催化、药物递送、成像和癌症化学光热疗法等应用中作为微反应器具有很高的应用潜力。
