Department of Biomedical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv 6997801, Israel.
Center for Physics and Chemistry of Living Systems, Tel Aviv University, Tel Aviv 6997801, Israel.
J Phys Chem Lett. 2024 Oct 24;15(42):10425-10434. doi: 10.1021/acs.jpclett.4c02022. Epub 2024 Oct 10.
Ratiometric probing of analytes presents a substantial advancement in molecular recognition, offering self-calibrating signals that enhance the measurement accuracy and reliability. We present a dual-emitting probe based on (6,5) chirality-enriched single-walled carbon nanotubes (SWCNTs) with oxygen defects for cholesterol (Chol) detection using ratiometric fluorescence readouts. The interaction with Chol induced significant intensity variations in the and emission peaks of oxygen defect-induced SWCNTs, giving rise to ratiometric fluorescence changes. The sensitivity of these probes toward Chol in water and serum was 0.28 ± 0.01 and 0.72 ± 0.05 μM, respectively, which is comparable to that of common gold standards for cholesterol detection used in clinical samples. By utilizing ratiometric readouts, our approach enhanced selectivity over numerous competing analytes, including amino acids, sugars, cations, anions, proteins, steroid hormones, surfactants, and phospholipids. Mechanistic investigations revealed that Chol detection by defect-integrated SWCNTs was facilitated by Chol incorporation within micelles formed by sodium cholate, the surfactant dispersant used for the SWCNT suspension. Oxygen defects played a crucial role by directly interacting with Chol. This strategy employing defect-integrated dual-peak NIR-emitting SWCNTs as sensors for Chol in aqueous and serum environments not only enables background-free detection of biologically relevant analytes but also advances biosensing using SWCNTs through tailored surface functionalization and advanced read-out concepts.
比率型探针在分子识别中具有重大进展，提供了自校准信号，提高了测量的准确性和可靠性。我们提出了一种基于（6,5）手性富单壁碳纳米管（SWCNTs）的双发射探针，具有氧缺陷，用于胆固醇（Chol）检测，采用比率荧光读出。与 Chol 的相互作用导致氧缺陷诱导的 SWCNTs 的 和 发射峰的强度发生显著变化，产生比率荧光变化。这些探针在水和血清中对 Chol 的灵敏度分别为 0.28 ± 0.01 和 0.72 ± 0.05 μM，与临床样本中常用的胆固醇检测金标准相当。通过利用比率读出，我们的方法增强了对多种竞争分析物的选择性，包括氨基酸、糖、阳离子、阴离子、蛋白质、甾体激素、表面活性剂和磷脂。机理研究表明，Chol 检测是通过胆酸钠形成的胶束内的 Chol 掺入来促进缺陷整合的 SWCNTs 进行的，胆酸钠是用于 SWCNT 悬浮液的表面活性剂分散剂。氧缺陷通过与 Chol 直接相互作用发挥了关键作用。这种策略采用缺陷整合的双峰近红外发射 SWCNTs 作为水相和血清环境中 Chol 的传感器，不仅能够实现生物相关分析物的无背景检测，而且通过定制表面功能化和先进的读出概念，推进了基于 SWCNTs 的生物传感。
