罗丹明6G的痕量检测需要具有较高的灵敏度，为提高SERS基底的增强因子从而提高检测灵敏度，设计了米花型SERS基底，采用有限元法对其拉曼增强效果进行仿真，模拟不同中心球半径r、米花花瓣轴a、b、c以及中心球与花瓣间距d条件下电场强度的变化，得出最佳结构参数，并计算其SERS增强因子。随后利用电化学沉积法制备该基底，并探究电压值以及柠檬酸三钠和AgNO₃的浓度配比对基底结构和性能的影响，从而制备出与理想物理模型形态最接近的米花型银/氮化钛薄膜基底。然后用其对罗丹明6G（R6G）进行痕量检测，探究该基底的拉曼增强效果以及稳定性。实验结果表明，当沉积电压为2V，柠檬酸三钠与AgNO₃浓度配比为1∶1 （2 mmol/L∶2 mmol/L）时，得到的米花型TiN-Ag复合SERS基底与理想化模型仿真形态最接近。经过计算得到该基底的增强因子可达10¹⁵，对罗丹明6G的检测限可达10⁻¹³ mol/L。实验结果证明设计的基底灵敏度高、稳定性强，可对食品非法添加剂的痕量检测提供技术支撑。

In this study, three-dimensional porous magnesium ferrite/titanium dioxide/reduced graphene oxide (MgFe₂O₄-GM/TiO₂/rGO (MGTG)) was successfully synthesized via green and hydrothermal-supported co-precipitation methods using the extract of Garcinia mangostana (G. mangostana) as a reducing agent. The characterization results indicate the successful formation of the nano/micro MgFe₂O₄ (MFO) and TiO₂ on the structure of the reduced graphene oxide (rGO), which can also act as efficient support, alleviating the agglomeration of the nano/micro MFO and TiO₂. The synergic effects of the adsorption and photodegradation activity of the material were investigated according to the removal of crystal violet (CV) under ultraviolet light. The effects of catalyst dosage, CV concentration, and pH on the CV removal efficiency of the MGTG were also investigated. According to the results, the CV photodegradation of the MGTG-200 corresponded to the pseudo-first-order kinetic model. The reusability of the material after 10 cycles also showed a removal efficiency of 92%. This happened because the materials can easily be recollected using external magnets. In addition, according to the effects of different free radicals ·O₂^?, h⁺, and ·OH on the photodegradation process, the photocatalysis mechanism of the MGTG was also thoroughly suggested. The antibacterial efficiency of the MGTG was also evaluated according to the inhibition of the Gram-positive bacteria strain Staphylococcus aureus (S. aureus). Concurrently, the antibacterial mechanism of the fabricated material was also proposed. These results confirm that the prepared material can be potentially employed in a wide range of applications, including wastewater treatment and antibacterial activity.

钛及其合金以其优异的机械性能和生物相容性而被广泛应用作硬组织植入器械, 但其表面缺乏生物活性以及植入后的炎症反应易导致骨整合不佳。本研究利用不同气氛中的热处理工艺调控氧化钛涂层的润湿性, 并研究表面润湿性能对免疫反应和成骨性能的影响规律。研究结果表明, 与亲水(接触角~10º)的氧化钛涂层相比, 处于亲水/疏水临界状态的氧化钛涂层(接触角’90º), 在仅培养巨噬细胞时, 抑制了巨噬细胞向M1促炎方向极化; 在共培养小鼠骨髓间充质干细胞和巨噬细胞时, 促进了巨噬细胞向M2抗炎方向极化, 同时显著上调了骨髓间充质干细胞成骨相关标记物的基因表达, 显示出更好的免疫促成骨性能。

骨科钛内置物存在感染的风险, 需要开发具有抗菌性、生物相容性且不易产生耐药性的表面涂层。通过电泳沉积15、30、45、60 s在微弧氧化(MAO)的钛表面制备了4组纳米氧化镁(MgO)涂层。MgO颗粒在MAO表面形成均匀涂层, 覆盖率随电泳时间延长。与金黄色葡萄球菌共培养6 h后, 4组样品抗菌率分别为1%、69%、83%、84%; 共培养24 h后抗菌率分别为81%、86%、89%、98%。显微观察发现MgO沉积样品表面黏附细菌密度、活细菌比例均随沉积时间延长而减少。与小鼠成骨细胞共培养1 d后, 4组样品存活率(相对空白孔板中所接种细胞)分别为108%、89%、53%、27%, 5 d后分别为139%、117%、112%、66%。荧光显微观察发现MAO样品表面未见死细胞, 而MgO沉积样品表面死细胞比例随沉积时间延长而增加, 但在实验周期(5 d)内均<5%。本研究表明电泳沉积30 s制备的MgO涂层具有良好的体外抗菌性和生物相容性。