In this study, a specifically-designed aggregation-induced emission fluorogen (AIEgen) with nanoparticle aggregates was used to quantitatively evaluate the bioaccumulation of Hg²⁺ and visualize Hg²⁺ kinetics in vivo within the rotifer Brachionus plicatilis for the first time. Quantitative results showed that a sharp drop in Hg²⁺ concentration occurred at the very beginning in the medium containing rotifers and Hg²⁺, showing a quick initial uptake of Hg²⁺ by the rotifers, and then the concentration in the medium plateaued after 5 min. With an increase in rotifer density, the amount of bioaccumulation increased in the rotifer. However, the bioaccumulation efficiency of Hg²⁺ decreased from 5.28 μg mg⁻¹ h⁻¹ at a low rotifer density of 0.093 mg ml⁻¹ to 2.61 μg mg⁻¹ h⁻¹ at a high rotifer density of 0.375 mg mL⁻¹. Moreover, the fluorescence images and spectra results illustrate that the ingestion of Hg²⁺ by the rotifer was via its mouth surrounded by the ciliary corona to the digestive tract, and Hg²⁺ could not permeate into the body integument through diffusion during the study period. Hg²⁺-induced fluorescence in rotifers dissipated in 6 h after staining, possibly through defecation and excretion. This study indicates that inorganic mercury can be quickly ingested by a rotifer via feeding, but is unlikely deposited as methylated mercury in rotifer tissues.

中文翻译：

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新型聚集诱导的发射氟纳米粒子对轮虫中汞离子生物累积的定量评估和体内可视化

在这项研究中，具有纳米颗粒聚集体的专门设计的聚集诱导的发射氟气（AIEgen）被用于定量评估轮虫Brachionus plicatilis中Hg ²⁺的生物累积并可视化Hg ²⁺的体内动力学。定量结果表明，在含有轮虫和Hg ²⁺的培养基中，Hg ²⁺浓度在开始时就出现了急剧下降，表明Hg ^2+的初始吸收迅速。通过轮虫，然后在5分钟后培养基中的浓度达到稳定。随着轮虫密度的增加，轮虫中的生物积累量增加。然而，汞的生物蓄积效率²⁺从5.28降低微克毫克^-1 ħ ^-1在0.093毫克ml的低轮虫密度^-1至2.61微克毫克^-1 ħ ^-1处的0.375高密度轮虫毫克毫升^-1。此外，荧光图像和光谱结果表明，轮虫摄入的Hg ²⁺是通过其被睫状冠状体包围的口进入消化道，而Hg ²⁺在研究期间不能通过扩散渗透到身体的皮被中。Hg ²⁺诱导的轮虫中的荧光在染色后6小时内消散，可能是通过排便和排泄引起的。这项研究表明，轮虫可以通过进食快速摄取无机汞，但不太可能以甲基化汞的形式沉积在轮虫组织中。