Auria-Luna Fernando, Foss Frank W, Molina-Canteras Juan, Velazco-Cabral Ivan, Marauri Aimar, Larumbe Amaia, Aparicio Borja, Vázquez Juan Luis, Alberro Nerea, Arrastia Iosune, Nacianceno Virginia San, Colom Adai, Marcuello Carlos, Jones Benjamin J P, Nygren David, Gómez-Cadenas Juan J, Rogero Celia, Rivilla Iván, Cossío Fernando P
Departamento de Química Orgánica I and Centro de Innovación y Química Avanzada (ORFEO-CINQA), Facultad de Química/Kimika Fakultatea, Universidad del País Vasco/Euskal Herriko Unibertsitatea (UPV/EHU) 20018 Donostia-San Sebastián Spain
Department of Chemistry and Biochemistry, University of Texas at Arlington Arlington Texas 76019 USA.
RSC Appl Interfaces. 2024 Nov 4;2(1):185-199. doi: 10.1039/d4lf00227j. eCollection 2025 Jan 16.
Translation of photophysical properties of fluorescent sensors from solution to solid-gas environments functionalized surfaces constitutes a challenge in chemistry. In this work, we report on the chemical synthesis, barium capture ability and photophysical properties of two families of monocolor and bicolor fluorescent sensors. These sensors were prepared to capture barium cations that can be produced in neutrinoless double beta decay of Xe-136. These sensors incorporate crown ether units, two different fluorophores, aliphatic spacers of different lengths, and a silatrane linker that forms covalent bonds with indium tin oxide (ITO) surfaces. Both species shared excellent Ba binding abilities. Fluorescent monocolor indicators (FMIs), based on naphthyl fluorophores, showed an off-on character in solution controlled by photoinduced electron transfer. Fluorescent bicolor indicators (FBIs), based on benzo[]imidazo[5,1,2-] fluorophores, exhibited a significant change in their emission spectra on going from the free to the barium-bound state. Both FMIs and FBIs showed similar photophysics in solution and on ITO. However, their performance on ITO was found to be attenuated, but not fully extinguished, with respect to the values obtained in solution, both in terms of intensity and selectivity between the free and Ba-bound states. Despite this issue, improved performance of the FBIs based on confocal microscopy of the directly attached molecules was observed. These selective FMI and FBI chemosensors installed on tailor-made functionalized surfaces are promising tools to capture the barium cations produced in the double beta decay of Xe-136. The identification of this capture would boost the sensitivity of the experiments searching for the Xe-136-based neutrinoless double beta decay, as backgrounds would be almost totally suppressed.
将荧光传感器的光物理性质从溶液环境转换到固 - 气环境及功能化表面是化学领域的一项挑战。在这项工作中，我们报告了两类单色和双色荧光传感器的化学合成、钡捕获能力及光物理性质。制备这些传感器是为了捕获在Xe - 136的无中微子双β衰变中产生的钡阳离子。这些传感器包含冠醚单元、两种不同的荧光团、不同长度的脂肪族间隔基以及一个与氧化铟锡（ITO）表面形成共价键的硅氮烷连接体。这两类物质都具有出色的钡结合能力。基于萘基荧光团的荧光单色指示剂（FMI）在溶液中表现出由光诱导电子转移控制的关 - 开特性。基于苯并[]咪唑[5,1,2 - ]荧光团的荧光双色指示剂（FBI）在从游离态转变为钡结合态时，其发射光谱发生了显著变化。FMI和FBI在溶液中和ITO上都表现出相似的光物理性质。然而，相对于在溶液中获得的值，无论是在强度方面还是在游离态和钡结合态之间的选择性方面，它们在ITO上的性能都有所衰减，但并未完全消失。尽管存在这个问题，但通过对直接附着分子的共聚焦显微镜观察，发现FBI的性能有所改善。这些安装在定制功能化表面上的选择性FMI和FBI化学传感器是捕获Xe - 136双β衰变中产生的钡阳离子的有前途的工具。这种捕获的识别将提高寻找基于Xe - 136的无中微子双β衰变实验的灵敏度，因为背景几乎可以完全被抑制。
