Shrake Robert, Demillo Violeta G, Ahmadiantehrani Mojtaba, Zhu Xiaoshan, Publicover Nelson G, Hunter Kenneth W
Department of Electrical and Biomedical Engineering, University of Nevada, Reno, NV, USA; Biomedical Engineering Program, University of Nevada, Reno, NV, USA.
Department of Chemical and Materials Engineering, University of Nevada, Reno, NV, USA.
J Colloid Interface Sci. 2015 Jan 1;437:140-146. doi: 10.1016/j.jcis.2014.09.020. Epub 2014 Sep 21.
Zwitterionic quantum dots prepared through incorporated zwitterionic ligands on quantum dot surfaces, are being paid significant attention in biomedical applications because of their excellent colloidal stability across a wide pH and ionic strength range, antifouling surface, good biocompatibility, etc. In this work, we report a dual-lipid encapsulation approach to prepare bioconjugatable zwitterionic quantum dots using amidosulfobetaine-16 lipids, dipalmitoyl-sn-glycero-3-phosphoethanolamine lipids with functional head groups, and CuInS2/ZnS quantum dots in a tetrahydrofuran/methanol/water solvent system with sonication. Amidosulfobetaine-16 is a zwitterionic lipid and dipalmitoyl-sn-glycero-3-phosphoethanolamine, with its functional head, provides bioconjugation capability. Under sonication, tetrahydrofuran/methanol containing amidosulfobetaine-16, dipalmitoyl-sn-glycero-3-phosphoethanolamine, and hydrophobic quantum dots are dispersed in water to form droplets. Highly water-soluble tetrahydrofuran/methanol in droplets is further displaced by water, which induces the lipid self-assembling on hydrophobic surface of quantum dots and thus forms water soluble zwitterionic quantum dots. The prepared zwitterionic quantum dots maintain colloidal stability in aqueous solutions with high salinity and over a wide pH range. They are also able to be conjugated with biomolecules for bioassay with minimal nonspecific binding.
通过在量子点表面引入两性离子配体制备的两性离子量子点，因其在较宽的pH和离子强度范围内具有出色的胶体稳定性、抗污表面、良好的生物相容性等，在生物医学应用中受到了广泛关注。在本工作中，我们报道了一种双脂质包封方法，使用氨磺酸甜菜碱-16脂质、具有功能性头部基团的二棕榈酰-sn-甘油-3-磷酸乙醇胺脂质以及CuInS2/ZnS量子点，在四氢呋喃/甲醇/水溶剂体系中通过超声处理来制备可生物共轭的两性离子量子点。氨磺酸甜菜碱-16是一种两性离子脂质，而带有功能性头部的二棕榈酰-sn-甘油-3-磷酸乙醇胺提供了生物共轭能力。在超声处理下，含有氨磺酸甜菜碱-16、二棕榈酰-sn-甘油-3-磷酸乙醇胺和疏水性量子点的四氢呋喃/甲醇分散在水中形成液滴。液滴中高度水溶性的四氢呋喃/甲醇进一步被水取代，这促使脂质在量子点的疏水表面自组装，从而形成水溶性两性离子量子点。所制备的两性离子量子点在高盐度水溶液和较宽的pH范围内均保持胶体稳定性。它们还能够与生物分子共轭，用于生物测定，且非特异性结合最少。
