Ghosh Madhusudan, Kadlag Sachin S, Bhosale Sheshanath V, Bhosale Sidhanath V, Swain Kallola K, Ghosh Ayan, Singh Prabhat K
Analytical Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085, India.
Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India.
ACS Appl Mater Interfaces. 2024 Oct 23;16(42):57004-57016. doi: 10.1021/acsami.4c10602. Epub 2024 Oct 8.
Thorium (Th) is commonly used in various applications, but its long-term exposure poses health risks, necessitating its detection in aqueous environments. Traditional methods such as inductively coupled plasma mass spectrometry are sensitive but require complex instrumentation. Optical sensors, particularly fluorometry-based methods, are simpler, cost-effective, and selective. However, developing effective aggregation-induced emission (AIE) turn-on sensors for Th(IV) requires water-soluble fluorophores with a low background fluorescence. In the present work, we report a turn-on detection method for Th(IV) based on the AIE of the fluorophore tetra(4-sulfophenyl) ethylene (SuTPE). Th(IV)-induced aggregation of SuTPE and the simultaneous drastic enhancement of the emission property of SuTPE have been utilized for the selective sensing of Th(IV) in 100% aqueous media. The sensing mechanism was explored using ground-state absorption, steady-state and time-resolved emission, FTIR, DLS, SEM, AFM and quantum chemical studies of the SuTPE-Th(IV) complex. The selectivity of the present probe toward Th(IV) ions has been established by studying the interference of several metal ions, including lanthanides and uranyl ions. The LOD for Th(IV) was estimated to be 240 nM (56 ppb). The performance of the probe was demonstrated in tap water and diluted seawater matrixes. This work provides a significant advance for Th(IV) detection in aqueous environments, with implications for environmental monitoring and health safety.
钍（Th）在各种应用中广泛使用，但其长期暴露会带来健康风险，因此需要在水环境中对其进行检测。传统方法如电感耦合等离子体质谱法虽灵敏，但需要复杂的仪器设备。光学传感器，特别是基于荧光法的方法，更简单、经济高效且具有选择性。然而，开发用于检测Th(IV)的有效聚集诱导发光（AIE）开启型传感器需要背景荧光低的水溶性荧光团。在本工作中，我们报道了一种基于荧光团四（4-磺酸苯基）乙烯（SuTPE）的AIE用于检测Th(IV)的开启型方法。利用Th(IV)诱导SuTPE聚集以及同时使SuTPE发射性能大幅增强，在100%水性介质中对Th(IV)进行选择性传感。通过对SuTPE-Th(IV)配合物进行基态吸收、稳态和时间分辨发射、傅里叶变换红外光谱（FTIR）、动态光散射（DLS）、扫描电子显微镜（SEM）、原子力显微镜（AFM）和量子化学研究，探索了传感机制。通过研究包括镧系元素和铀酰离子在内的几种金属离子的干扰，确定了本探针对Th(IV)离子的选择性。估计Th(IV)的检测限为240 nM（56 ppb）。在自来水和稀释海水基质中展示了该探针的性能。这项工作为水环境中Th(IV)的检测取得了重大进展，对环境监测和健康安全具有重要意义。
