Wilson Quintashia D, Lin Helen H, Lin Eric Y, Chen Lin-Jiun, Sletten Ellen M
Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California 90095, United States.
Anal Chem. 2025 Mar 18;97(10):5595-5604. doi: 10.1021/acs.analchem.4c06185. Epub 2025 Mar 4.
Merocyanine dyes are a versatile class of donor-acceptor polymethine dyes that exhibit unique properties depending on their structural makeup and surrounding environment. Scaffolds that favor the cyanine state (., narrow, red-shifted absorption and high fluorescence quantum yields) in biologically relevant settings are highly advantageous for multiplexed labeling experiments, but remain limited by their visible absorption. Herein, we synthesize a new class of far-red (650-700 nm) to near-infrared (NIR, 700-1000 nm) flavylium merocyanine dyes and demonstrate that, unlike conventional scaffolds, they favor the cyanine state with increasing solvent viscosity and hydrogen bond donation, rather than polarity. We leverage these advantageous properties for live cell labeling, where we observed intrinsic targeting to the endoplasmic reticulum (ER) and lipid droplets, and minimal crosstalk with commercial stains. We reveal that intrinsic ER labeling is achieved by the dipolarity in the cyanine state and lipophilicity (Clog) of the merocyanine architecture, making this class of dyes a simple, red-shifted alternative to the more structurally complex ER stains currently available.
部花青染料是一类多功能的供体-受体聚甲炔染料，其性质独特，取决于其结构组成和周围环境。在生物相关环境中有利于花青状态（即窄的、红移吸收和高荧光量子产率）的支架对于多重标记实验非常有利，但仍受其可见吸收的限制。在此，我们合成了一类新型的远红（650 - 700 nm）到近红外（NIR，700 - 1000 nm）的黄鎓部花青染料，并证明与传统支架不同，随着溶剂粘度和氢键供体能力增加，而不是极性增加，它们有利于花青状态。我们利用这些有利性质进行活细胞标记，在此过程中我们观察到其对内质网（ER）和脂滴的内在靶向性，以及与商业染料的最小串扰。我们发现，内质网的内在标记是通过花青状态的偶极矩和部花青结构的亲脂性（Clog）实现的，这使得这类染料成为目前可用的结构更复杂的内质网染料的一种简单的、红移替代物。
