Chromium (Cr(VI)), a highly toxic metal-oxyanion which is carcinogenic and mutagenic to humans, is a severe environmental pollutant. Developing simple methods for sensitive and selective detection of Cr(VI) is of great significance. In this work, fluorescent silicon nanoparticles (SiNPs) with good water solubility were facilely synthesized via a one-step hydrothermal method by using (3-aminopropyl)triethoxysilane (APTES) as the silicon source and natural antioxidant quercetin as the reducing agent. The obtained SiNPs displayed good thermostability, salt-tolerance and photo-stability. The as-prepared SiNPs exhibited bright blue emission at 437 nm under excitation at 362 nm, allowing them to be developed as a fluorescent probe for detection of Cr₂O₇²⁻. Significantly, the fluorescence of the SiNPs could be remarkably quenched by Cr₂O₇²⁻ via the internal filtering effect (IFE). Based on this phenomenon, a novel fluorescence method for detection of Cr₂O₇²⁻ was established. A good linear relationship was obtained from 0.5 to 100 μM with a limit of detection (based on 3 s/k, LOD) of 180 nM. The proposed fluorescence method was successfully applied to the detection of Cr₂O₇²⁻ in tap water. Moreover, a fluorescent filter paper sensor was developed for the visual detection of Cr₂O₇²⁻, providing a valuable platform for Cr₂O₇²⁻ sensing in a convenient way.

中文翻译：

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一锅合成用于选择性Cr2O72-传感的新型水分散性荧光硅纳米粒子

铬（Cr（VI））是一种剧毒的金属氧阴离子，对人体具有致癌性和致突变性，是一种严重的环境污染物。开发用于敏感和选择性检测Cr（VI）的简单方法具有重要意义。在这项工作中，以（3-氨基丙基）三乙氧基硅烷（APTES）为硅源，以天然抗氧化剂槲皮素为还原剂，通过一步水热法轻松合成了水溶性良好的荧光硅纳米粒子（SiNPs）。所获得的SiNP显示出良好的热稳定性，耐盐性和光稳定性。所制备的SiNP在362 nm激发下在437 nm处表现出亮蓝色发射，使其可以开发为荧光探针以检测Cr ₂O ₇ ²⁻。值得注意的是，SiNPs的荧光可以通过内部过滤效应（IFE）被Cr ₂ O ₇ ^2- 显着淬灭。基于这种现象，建立了一种检测Cr ₂ O ₇ ^2-的新型荧光方法。从0.5到100μM获得了良好的线性关系，检测极限（基于3 s / k，LOD）为180 nM。所提出的荧光方法已成功应用于自来水中Cr ₂ O ₇ ^2-的检测。此外，开发了用于视觉检测Cr ₂的荧光滤纸传感器O ₇ ^2-，以方便的方式为Cr ₂ O ₇ ^2-的感测提供了有价值的平台。