采用一锅法制备量子点/琼脂纳米复合凝胶

以天然高分子琼脂为稳定剂，采用简单便捷的一锅法制备Mn掺杂ZnS量子点/琼脂纳米复合凝胶，琼脂不仅作为制备量子点的稳定剂，同时也是纳米复合凝胶的主要成分。对该纳米复合凝胶中量子点的化学结构和尺寸大小进行了表征，并对纳米复合凝胶的荧光性能和凝胶性能进行了研究。实验结果表明，制备得到的纳米复合凝胶均一稳定，在302 nm紫外光下呈现十分明显的橙红色荧光。在该纳米复合凝胶的透射电子显微镜（TEM）表征中可以观察到大小比较均一、粒径为3 nm左右的纳米粒子，光谱分析结果进一步证实纳米复合凝胶中存在Mn掺杂ZnS量子点。该纳米复合凝胶不仅具有良好的荧光性能，还具有温度刺激响应性可逆溶胶-凝胶转变性能，同时具有较高的溶胶转变温度和较好的温度稳定性。利用这些性能特点，可以方便地制备纳米复合凝胶小球。此外，该纳米复合凝胶还可以被潜在应用于金属离子的荧光检测分析领域。

Preparation of quantum dots/agar nanocomposite gel by one-pot approach

Herein, for the first time, a Mn-doped ZnS quantum dots (QDs)/agar nanocomposite gel was prepared by a simple and convenient one-pot approach. In this approach, agar was not only used as the stabilizing agent for preparing Mn-doped ZnS QDs, but also served as the main ingredient in the resulting nanocomposite gel. The chemical structure and size of the QDs in the nanocomposite gel were characterized. The fluorescence property and gel property of the nanocomposite gel were investigated. The prepared Mn-doped ZnS QDs/agar nanocomposite gel is homogeneous and stable, showing a typical orange fluorescence under 302 nm UV light. Moreover, TEM observation shows that there are nanoparticles with relatively uniform size in the nanocomposite gel. The average size of these nanoparticles is about 3 nm. The UV-vis absorption spectroscopy and fluorescence spectroscopy both prove that there are Mn-doped ZnS QDs in the nanocomposite gel. The prepared nanocomposite gel not only possesses a typical fluorescence feature that comes from Mn-doped ZnS QDs, but also has a thermo-responsive sol-gel transition property which is attributed to agar. In addition, the nanocomposite gel shows good thermal stability due to the high sol transition temperature. By taking advantage of the above properties, nanocomposite gel beads can be conveniently fabricated. Furthermore, the prepared nanocomposite gel can be potentially applied for fluorescence detection and analysis of metal ions.