Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada.
ACS Appl Mater Interfaces. 2023 Dec 6;15(48):55456-55465. doi: 10.1021/acsami.3c13430. Epub 2023 Nov 20.
Semiconducting polymer dots (Pdots) are brightly fluorescent nanoparticles of growing interest for bioanalysis and imaging. A recurring challenge with these materials is obtaining robust physical and colloidal stability and low nonspecific binding. Here, we prepared and characterized Pdots with bovine serum albumin (BSA) as the stabilizing agent (BSA-Pdots) instead of a more conventionally used amphiphilic polymer, both without and with cross-linking of the protein using glutaraldehyde (BSA(GA)-Pdots) or disuccinimidyl glutarate. Characterization included fluorescence properties; colloidal stability as a function of pH, ionic strength, and solvent perturbation; shape retention and hardness; and nonspecific binding with common assay substrates, fixed cells, and live cells. These properties were contrasted with the same properties for amphiphilic polymer-stabilized Pdots and silica-coated Pdots. On balance, the BSA-stabilized Pdots were similar or more favorable in their properties, with BSA(GA)-Pdots being especially advantageous. Bioconjugation of the BSA-stabilized Pdots was possible using amine-reactive active-ester chemistry, including biotinylation and bioorthogonal functionalization for immunoconjugation via tetrazine-strained-alkene click chemistry. These approaches were used for selective fluorescent labeling of cells based on ligand-receptor and antibody-antigen binding, respectively. Overall, direct BSA stabilization is a very promising strategy for preparing Pdots with improved physical and colloidal stability, reduced nonspecific interactions, and utility for in vitro diagnostics and other bioanalyses and imaging.
半导体聚合物点（Pdots）是一种荧光纳米粒子，由于其在生物分析和成像方面的应用而备受关注。这些材料的一个反复出现的挑战是获得稳健的物理和胶体稳定性以及低的非特异性结合。在这里，我们使用牛血清白蛋白（BSA）作为稳定剂（BSA-Pdots）而不是更常规使用的两亲聚合物来制备和表征 Pdots，而无需使用戊二醛（BSA（GA）-Pdots）或琥珀酰亚胺基琥珀酸酯交联蛋白质。表征包括荧光特性；胶体稳定性作为 pH、离子强度和溶剂扰动的函数；形状保留和硬度；以及与常见测定底物、固定细胞和活细胞的非特异性结合。将这些特性与两亲聚合物稳定的 Pdots 和硅烷涂层的 Pdots 的相同特性进行了对比。总的来说，BSA 稳定的 Pdots 在其性质上相似或更有利，其中 BSA（GA）-Pdots 尤其有利。BSA 稳定的 Pdots 可以通过胺反应性活泼酯化学进行生物偶联，包括生物素化和生物正交功能化，用于通过四嗪-应变-烯点击化学进行免疫偶联。这些方法分别用于基于配体-受体和抗体-抗原结合的细胞的选择性荧光标记。总的来说，直接 BSA 稳定化是一种非常有前途的策略，可用于制备具有改进的物理和胶体稳定性、降低非特异性相互作用以及用于体外诊断和其他生物分析和成像的 Pdots。
