基于核酸适体的试纸条检测三磷酸腺苷

将核酸适体（Aptamer）的特异性与纳米金颗粒的独特光学性质相结合,制备了一种适用于小分子检测的干式试纸条。该试纸条以修饰功能化核酸适体（PloyT13-Aptamer）的纳米金为识别元件,在控制线（C）上修饰ployA13序列,与识别元件结合以判断试纸条的有效性;在测试线（T）上修饰与Aptamer部分互补的DNA序列,与待测物形成竞争关系,通过T线上纳米金显色的深浅来定性或定量分析待测物浓度。结果表明,优化实验条件下,观察T线颜色变化可实现三磷酸腺苷（ATP）的肉眼定性检测,视觉检出限为10μmol/L。使用Image J软件进行定量分析,试纸条检测范围为10～1000μmol/L,检出限为2.4μmol/L。该试纸条生物传感器可以在10 min内得出检测结果且特异性良好,血清中回收率为104.4%～119.0%,为ATP的现场快速检测提供了一种经济有效的方法。     

Transformation from β-Ga2O3 to GaN Nanowires via Nitridation

Element doping is an important way to modify the properties of semiconductor materials. In our previous work, it was found that nitrogen-doping in β-Ga2O3 nanowires can induce a novel luminescence emission （around 740 nm） caused by generation of acceptor levels at the middle of the band gap of the β-Ga2O3 nanowires. Here we report that further heavy doping of nitrogen can transform the β-Ga2O3 nanowires completely into wurtzite structured GaN nanowires. Transmission electron microscopy （TEM）, x-ray diffraction （XRD） and Raman spectrum are used to evaluate the transition process. Both XRD and Raman analysis reveal that the monoclinic β-Ga2O3 nanowires start phase transformation at a temperature around 850℃ towards wurtzite structured GaN. Our results will be very helpful to profound our understanding of the doping induced effects and phase transformation in semiconductor compounds.     

Room Temperature Ferromagnetism and Optical Tunability in Cu Doped GaN Nanowires

GaN nanowires doped with 2at.% and 6at.% Cu ions are synthesized by chemical vapour deposition method. Structural and compositional analyses demonstrate that the as-grown nanowires are of single crystal wurtzite GaN structure. Magnetic characterizations reveal that the doped GaN nanowires exhibit room temperature ferromagnetism. The measured saturation magnetic moments are 0.37ug and 0.47ug per Cu atom at 300 K for Cu 2 at. % and 6 at. %, respectively. The photoluminescence spectra show that Cu dopant can tune the band gap of the GaN, which leads to a red shift of band-edge emission with increasing dopant concentration.     

Co掺杂ZnO纳米棒的水热法制备及其光致发光性能

以Zn(NO3)2·6H2O 和Co(NO3)2·6H2O为原料, 通过水热法在较低温度下制备了纯ZnO和Co掺杂的ZnO(ZnO:Co)纳米棒. 利用XRD、EDS、TEM和HRTEM对样品进行了表征, 结合光致发光(PL)谱研究了样品的PL性能. 结果表明, 水热法制备纯ZnO和ZnO:Co纳米棒均具有较好的结晶度. Co2+是以替代的形式进入ZnO晶格, 掺入量为2%(原子分数)左右. 纯的ZnO纳米棒平均直径约为20 nm, 平均长度约为180 nm; 掺杂样品的平均直径值约为15 nm, 平均长度约为200 nm左右; Co掺杂轻微地影响ZnO纳米棒的生长. 另外, Co掺杂能够调整ZnO纳米棒的能带结构、提高表面态含量, 进而使得ZnO:Co纳米棒的紫外发光峰位红移, 可见光发光能力增强.