美国康奈尔大学Chen, Peng团队报道了单一合成聚合物的光学测序。相关研究成果于2023年11月9日发表在《自然—化学》。

合成聚合物的微观序列在聚合物性能中起着至关重要的作用，但通常是未知的，传统测量无法获得。

该文中，研究人员报道了在活性聚合条件下单个合成共聚物链的实时光学测序。通过使用CREAS（超分辨率成像的耦合反应方法）以单体分辨率对单催化剂的聚合物生长进行多色成像来实现这一点。CREATS使反应有效地产生荧光，使单分子定位显微镜能够在更高的反应物浓度下观察化学反应。研究数据表明，表面接枝聚合的链传播动力学包含具有定义的记忆时间（可归因于相邻单体相互作用）和链长依赖性（由于表面静电效应）的时间波动。

此外，单个共聚物的微观序列揭示了它们形成嵌段共聚物的趋势，更重要的是，量化了单个嵌段的尺寸分布，以与理论上无规共聚物进行比较。这种测序能力为合成聚合物的单链级结构-功能相关性研究铺平了道路。合成聚合物的序列通常是不均匀的，并决定了它们的许多物理化学性质，但很难确定。现在，一种称为CREAS（超分辨率成像的耦合反应方法）的成像方法可以在（共）聚合过程中计数、定位和识别单个聚合物链的每个单体。

附：英文原文

Title: Optical sequencing of single synthetic polymers

Author: Ye, Rong, Sun, Xiangcheng, Mao, Xianwen, Alfonso, Felix S., Baral, Susil, Liu, Chunming, Coates, Geoffrey W., Chen, Peng

Issue&Volume: 2023-11-09

Abstract: Microscopic sequences of synthetic polymers play crucial roles in the polymer properties, but are generally unknown and inaccessible to traditional measurements. Here we report real-time optical sequencing of single synthetic copolymer chains under living polymerization conditions. We achieve this by carrying out multi-colour imaging of polymer growth by single catalysts at single-monomer resolution using CREATS (coupled reaction approach toward super-resolution imaging). CREATS makes a reaction effectively fluorogenic, enabling single-molecule localization microscopy of chemical reactions at higher reactant concentrations. Our data demonstrate that the chain propagation kinetics of surface-grafted polymerization contains temporal fluctuations with a defined memory time (which can be attributed to neighbouring monomer interactions) and chain-length dependence (due to surface electrostatic effects). Furthermore, the microscopic sequences of individual copolymers reveal their tendency to form block copolymers, and, more importantly, quantify the size distribution of individual blocks for comparison with theoretically random copolymers. Such sequencing capability paves the way for single-chain-level structure–function correlation studies of synthetic polymers. Sequences of synthetic polymers are generally heterogeneous and dictate many of their physiochemical properties, but are challenging to determine. Now an imaging method, termed CREATS (coupled reaction approach toward super-resolution imaging), can count, localize and identify each monomer of single polymer chains during (co)polymerization.

DOI: 10.1038/s41557-023-01363-2

Source: https://www.nature.com/articles/s41557-023-01363-2