Liu Chang, Han Yandong, Wang Zhongshun, Zhang Lin, Yang Wensheng
State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun 130012, China.
Engineering Research Center for Nanomaterials, Henan University, Kaifeng 475000, China.
Langmuir. 2024 Jun 18;40(24):12565-12572. doi: 10.1021/acs.langmuir.4c01027. Epub 2024 Jun 5.
Silica particles modified with amino groups hold immense potential across diverse fields, owing to their distinctive properties. The widely adopted method of surface modification, utilizing (3-aminopropyl)triethoxysilane (APTES), facilitates the incorporation of amino-functional groups onto the silica surface, thereby creating sites for subsequent functionalization with other molecules. In this context, the ability to precisely tailor the surface properties of amino-functionalized silica particles is crucial for optimizing their performance in various applications. In this work, we systematically investigated the influence of the APTES concentration and water content on the density of amino groups grafted on the silica surface within an ethanol-water mixture. The rational control of hydrolysis and condensation of APTES enabled the precise regulation of the amino density on the silica surface, resulting in a notable shift in the isoelectric point from 2.9 to 9.2. Subsequently, we assembled amino-functionalized silica with different isoelectric points with gold nanoparticles to demonstrate their tunable ability as surface-enhanced Raman scattering (SERS) substrates. This controlled and tailored amino-functionalization process opens up new routes for fine-tuning the properties of silica particles, thereby expanding their utility across various applications in materials science, nanotechnology, and biomedicine.
由于其独特的性质，氨基修饰的二氧化硅颗粒在各个领域都具有巨大的潜力。广泛采用的表面改性方法是利用（3-氨丙基）三乙氧基硅烷（APTES），它有助于将氨基官能团引入二氧化硅表面，从而为后续与其他分子的功能化创造位点。在这种情况下，精确调整氨基官能化二氧化硅颗粒的表面性质对于优化其在各种应用中的性能至关重要。在这项工作中，我们系统地研究了在乙醇-水混合物中，APTES浓度和含水量对接枝在二氧化硅表面的氨基密度的影响。对APTES水解和缩合的合理控制能够精确调节二氧化硅表面的氨基密度，导致等电点从2.9显著移至9.2。随后，我们将具有不同等电点的氨基官能化二氧化硅与金纳米颗粒组装在一起，以展示它们作为表面增强拉曼散射（SERS）基底的可调谐能力。这种可控且定制的氨基官能化过程为微调二氧化硅颗粒的性质开辟了新途径，从而扩展了它们在材料科学、纳米技术和生物医学等各种应用中的效用。
