State Key Laboratory of Analytical Chemistry for Life Science, School of Life Sciences, Nanjing University, Nanjing 210023, PR China.
Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Science, Nanjing Forestry University, Nanjing 210037, PR China.
Anal Chem. 2024 Oct 1;96(39):15720-15727. doi: 10.1021/acs.analchem.4c03365. Epub 2024 Sep 16.
Colorimetric assays have been extensively investigated for biosensing applications due to their advantages of visual recognizability, ease of use, and low cost. However, advancing their development is a great challenge due to the inherent limitations of colorimetric dyes. Herein, we report a strategy to assemble dyes in covalent organic frameworks (COFs) to effectively reinforce the applicability of pH-responsive dyes in colorimetric bioassays. Experimental results reveal that three-dimensional COFs can promote the assembly of dyes through hydrogen bonding, resulting in the formation of a dye-supermolecule@COF assembly. Consequently, when sensitized at increased pH levels (e.g., hydroxyl ions), disruption of hydrogen bonds may trigger a rapid transition from their insoluble fixed state within the COFs into soluble, visibly detectable dye anions. This process can also be facilitated by increased hydrophilicity and elevated electrostatic repulsion between the dye anions and COFs, leading to the substantial release of chromogenic dye anions from the COF pores into the solution, thereby amplifying the colorimetric signal output. Therefore, by employing various synthesized dye-supermolecule@COFs as signal tags, we developed a colorimetric bioassay capable of accurately identifying breast cancer cell subtypes. This study not only highlights the effectiveness of dye-supermolecule@COFs in enhancing colorimetric biosensing but also underscores the potential of employing the COF-mediated dye assembly strategy for colorimetric assays.
由于比色分析具有目视识别、使用方便和成本低等优点，因此在生物传感应用中得到了广泛的研究。然而，由于比色染料固有的局限性，推进其发展是一个巨大的挑战。在此，我们报告了一种将染料组装在共价有机框架（COFs）中的策略，以有效地增强 pH 响应染料在比色生物分析中的适用性。实验结果表明，三维 COFs 可以通过氢键促进染料的组装，从而形成染料超分子@COF 组装体。因此，当在较高 pH 值（例如，羟基离子）下敏化时，氢键的破坏可能会触发它们在 COFs 内从不可溶的固定状态迅速转变为可溶的、可视觉检测的染料阴离子。这种过程还可以通过增加染料阴离子和 COFs 之间的亲水性和静电排斥来促进，从而导致大量生色染料阴离子从 COF 孔中释放到溶液中，从而放大比色信号输出。因此，通过将各种合成的染料超分子@COFs 用作信号标签，我们开发了一种能够准确识别乳腺癌细胞亚型的比色生物分析方法。本研究不仅突出了染料超分子@COFs 在增强比色生物传感方面的有效性，还强调了采用 COF 介导的染料组装策略进行比色分析的潜力。
