Biocompatible nanosystems exhibiting long-lifetime (∼millisecond) luminescence features are particularly relevant in the field of bioimaging. In this study, citrate-functionalized calcium-doped europium phosphates nanophosphors of the rhabdophane type were prepared at different synthesis times by a bioinspired crystallization route, consisting in thermal decomplexing of Ca²⁺/Eu³⁺ /citrate/phosphate/carbonate solutions. The general formula of this material is Ca_αEu_1-α(PO₄)_1-α(HPO₄)_α·nH₂O, with α ranging from 0 to 0.58 and n ∼ 1. A thorough characterization of the nanoparticles has been carried out by XRD (including data processing with Topas 6.0), HR-TEM, TEM, FTIR, TG/DTA, ICP, dynamic light scattering (DLS), electrophoretic mobility, and fluorescence spectroscopy. Based on these results a crystallization mechanism involving the filling of cationic sites with Ca²⁺ions associated to a concomitant adjustment of the PO₄/HPO₄ ratio was proposed. Upon calcium doping, the aspect ratio of the nanoparticles as well as of the crystalline domains decreased and the relative luminescence intensity (R.L.I.) could be modulated. Neither the pH nor the ionic strength, nor the temperature (from 25 to 37 °C) affected significantly the R.L.I. of particles after resuspension in water, leading to rather steady luminescence features usable in a large domain of conditions. This new class of luminescent compounds has been proved to be fully cytocompatible relative to GTL-16 human carcinoma cells and showed an improved cytocompatibility as the Ca²⁺ content increased when contacted with the more sensitive m17. ASC murine mesenchymal stem cells. These biocompatible nanoparticles thus appear as promising new tailorable tools for biomedical applications as luminescent nanoprobes.

表现出长寿命（〜毫秒）发光特征的生物相容性纳米系统在生物成像领域特别重要。在这项研究中，通过生物启发的结晶途径在不同的合成时间制备了横纹烷类型的柠檬酸盐官能化的钙掺杂的磷酸euro磷纳米磷酸盐，包括Ca ²⁺ / Eu ³⁺ /柠檬酸盐/磷酸盐/碳酸盐溶液的热分解。该材料的通式为Ca _α的Eu _1-α（PO ₄）_1-α（HPO ₄）_α ·nH的₂O，α的范围为0到0.58，n约为1。通过XRD（包括使用Topas 6.0进行数据处理），HR-TEM，TEM，FTIR，TG / DTA，ICP，动态对纳米颗粒进行了全面表征。光散射（DLS），电泳迁移率和荧光光谱。基于这些结果，结晶机理涉及用Ca ²⁺离子填充阳离子位点，同时伴随着PO ₄ / HPO _4的调节。提出了比率。钙掺杂后，纳米颗粒的长宽比以及晶域的长宽比降低，并且可以调节相对发光强度（RLI）。再悬浮于水中后，pH值，离子强度或温度（25至37°C）都不会显着影响颗粒的RLI，不会导致在较大范围的条件下均可使用的稳定发光特性。这类新的发光化合物已被证明相对于GTL-16人类癌细胞具有完全的细胞相容性，并显示出改善的细胞相容性，例如Ca ²⁺与更敏感的m17接触时，血红蛋白含量增加。ASC鼠间质干细胞。这些生物相容性纳米粒子因此像发光纳米探针一样，有望成为用于生物医学应用的新的可定制工具。