一种用于多巴胺实时检测的集成微电极的微流控芯片

设计并制作了一种用于多巴胺实时检测的集成微电极的微流控芯片。芯片由一片聚二甲基硅氧烷( PDMS)沟道片和一片玻璃电极片组成,在PDMS沟道片上集成了用作细胞培养室的主通道和用于培养基输送的两条侧通道,在玻璃电极片上集成了用于多巴胺实时检测的微电极。为了解决PDMS沟道片与硅模具之间的脱模困难问题,研究了一种新的脱模方法。建立了一种Au-Au-Au三电极体系,表现出了良好的电化学检测性能。以溶解在神经干细胞培养基中的多巴胺为测试样品,对芯片的性能进行了初步研究。多巴胺的检出限为3.92μmol/L,线性检测范围为10~500μmol/L,片间的检测重复精度小于4%。     

CdTe量子点作为荧光探针测定水环境中微量镉离子

利用CdTe量子点(QDs)和乙二胺四乙酸(EDTA)构建的纳米探针,建立了一种能快速灵敏检测Cd2+的新方法。利用EDTA溶液与Cd2+的络合作用对QDs的表面进行化学蚀刻,在QDs表面形成了Cd2+的空腔,这些表面缺陷使得QDs荧光猝灭,而继续加入Cd2+后,新加入的Cd2+能够迅速补位空腔修复表面缺陷,使得QDs的荧光恢复。在最佳的实验条件下,当Cd2+浓度在3.3×10-9~6.7×10-6mol/L范围时,QDs恢复的荧光强度与Cd2+浓度之间呈良好的线性关系,检出限为1.0×10-9mol/L(S/N=3)。此外,相对于其他金属离子,该荧光探针对Cd2+具有高选择性,并且将其用于实际水样中Cd2+含量的检测,结果令人满意。     

用于细胞三维培养的集成微柱阵列的微流控芯片设计与验证

设计并验证了一种用于细胞三维培养的集成微柱阵列的微流控芯片.芯片由一片聚二甲基硅氧烷(PDMS)沟道片和一片玻璃盖片组成, 在PDMS沟道片上集成了一个由两排微柱阵列围成的细胞培养室和两条用于输送培养基的侧沟道.微柱间距直接影响了芯片的使用性能, 是整个芯片设计的关键.基于数值模拟和实验验证, 本研究对微柱间距进行了优化设计.优化后的微流控芯片可以很好地实现细胞与细胞外基质模拟材料混合液的稳定注入、培养基中营养物质向培养室内的快速扩散和细胞代谢物的及时排出.在芯片上进行了神经干细胞的三维培养, 证明了芯片上构建的细胞体外微环境的稳定性.     

Molecular dynamics simulation of interaction between nanorod and phospholipid molecules bilayer

Natural and artificially prepared nanorods' surfaces have proved to have good bactericidal effect and self-cleaning property. In order to investigate whether nanorods can kill the enveloped virus, like destroying bacterial cell, we study the interaction between nanorods and virus envelope by establishing the models of nanorods with different sizes as well as the planar membrane and vesicle under the Dry Martini force field of molecular dynamics simulation. The results show that owing to the van der Waals attraction between nanorods and the tail hydrocarbon chain groups of phospholipid molecules, the phospholipid molecules on virus envelope are adsorbed to nanorods on a large scale. This process will increase the surface tension of lipid membrane and reduce the order of lipid molecules, resulting in irreparable damage to planar lipid membrane. Nanorods with different diameters have different effects on vesicle envelope, the larger the diameter of nanorod, the weaker the van der Waals effect on the unit cross-sectional area is and the smaller the degree of vesicle deformation. There is synergy between the nanorods in the nanorod array, which can enhance the speed and scale of lipid adsorption. The vesicle adsorbed in the array are difficult to desorb, and even if desorbed, vesicle will be seriously damaged. The deformation rate of the vesicle adsorbed in the nanorod array exceeds 100%, implying that the nanorod array has a strong destructive effect on the vesicle. This preliminarily proves the feasibility of nanorod array on a surface against enveloped virus, and provides a reference for the design of corresponding nanorods surface.