Synthesizing Red Fluorescent Carbon Dots from Rigid Polycyclic Conjugated Molecules: Dual-Mode Sensing and Bioimaging in Biochemical Applications

Red fluorescent carbon dots (R-CDs) are special desirable for biochemical analysis due to good biological compatibility and deep penetration; however, they remain as bottlenecks due to difficulties in expanding the sp² domain, especially those are fused from rigid polycyclic conjugated molecules (RPCMs) with heteroatom substituents due to huge steric hindrance and heteroatom blockage toward graphic lattice. Here, an RPCM with heteroatom substituents, 1,5-diamino-4,8-dihydroxyanthraquinone (DDAQ), based self-doped R-CDs with PL emission at 635 nm is reported. Further investigations reveal that the expanding, hybrid sp² domain with indanthrone tannin structure from DDAQ is mainly responsible for the obtained red fluorescence of R-CDs. Taking advantage of optical properties, R-CDs are considered to construct a colorimetric/fluorescent dual mode sensing array for quantifying trace levels of Fe³⁺ and glyphosate based on the static quenching, and a biomarker for cell imaging. The CD-based sensors exhibit outstanding recovery, high selectivity, and sensitivity, also facilitated dual-mode detection with the naked-eye. The R-CDs have low cytotoxicity, good cell membrane penetration for rapid cell entry, and high resolution, demonstrating their potential for biolabeling and bioanalytic applications.     

明胶固定辣根过氧化物酶制备H_2O_2传感器

用明胶将辣根过氧化物酶(HRP)固定于多壁碳纳米管(MWNT)和茜素红(AR)修饰的玻碳(GC)电极上,制成HRP生物传感器(HRP/AR/MWNT/GC),然后在3%戊二醛(GA)中进行交联改性,以克服明胶膜易溶胀的缺点,并提高膜的稳定性.同时详细探讨了该传感器对H2O2的响应性能,并优化了实验条件.结果表明,该传感器对H2O2的线性响应范围为5.0×10-6～1.0×10-3mol/L,线性相关系数为0.9932,检出限为1.0×10-7mol/L,且放于4℃环境30d后,峰电流值约为原来的72.1%.该传感器响应快速,灵敏度高,且具有良好的重现性、稳定性及较长的使用寿命,具有潜在的应用价值.     

超细红色荧光粉LaMgAl_(11)O_(19):Eu~(3+)的制备与发光性能

采用凝胶-燃烧法制备了稀土Eu3+掺杂的LaMgAl11O19红色荧光粉的前驱粉末,在低于700℃退火处理时,得到非晶态样品,而高于850℃退火处理后为单一六方相结构LaMgAl11O19:Eu3+样品.SEM结果表明,该法制备的样品为颗粒分布均匀,粒径在200～400nm之间的超细粉末.通过激发光谱和发射光谱研究了Eu3+在LaMgAl11O19基质中的发光性能,结果显示,非晶态和晶态La1-xMgAl11O19:xEu3+样品都可发光,在613nm波长光的监测下所得荧光粉的激发光谱为一宽带和系列锐峰,其最强激发峰出现在蓝光465nm处,次强峰为394nm,表明该荧光粉与广泛使用的紫外和蓝光LED芯片的输出波长相匹配.在465nm波长光的激发下观察到超细LaMgAl11O19粉末中Eu3+的613nm(5D0→7F2)强的特征发射,且随着粉末逐渐成相5D0→7F2跃迁明显增强,说明LaMgAl11O19:Eu3+超细粉末可作为白光LED的红色补偿荧光粉.     

Extraction methods of red blood cell membrane proteins for Multidimensional Protein Identification Technology (MudPIT) analysis

Since red blood cells (RBCs) lack nuclei and organelles, cell membrane is their main load-bearing component and, according to a dynamic interaction with the cytoskeleton compartment, plays a pivotal role in their functioning. Even if erythrocyte membranes are available in large quantities, the low abundance and the hydrophobic nature of cell membrane proteins complicate their purification and detection by conventional 2D gel-based proteomic approaches. So, in order to increase the efficiency of RBC membrane proteome identification, here we took advantage of a simple and reproducible membrane sub-fractionation method coupled to Multidimensional Protein Identification Technology (MudPIT). In addition, the adoption of a stringent RBC filtration strategy from the whole blood, permitted to remove exhaustively contaminants, such as platelets and white blood cells, and to identify a total of 275 proteins in the three RBC membrane fractions collected and analysed. Finally, by means of software for the elaboration of the great quantity of data obtained and programs for statistical analysis and protein classification, it was possible to determine the validity of the entire system workflow and to assign the proper sub-cellular localization and function for the greatest number of the identified proteins.     

胶束增敏分光光度法水相测定乳制品中三聚氰胺

建立了一种基于胶束增敏缔合反应水相测定乳制品中三聚氰胺的分光光度法,研究了在阴离子表面活性剂十二烷基硫酸钠(SDS)形成的胶束体系中,茜素红(AR)阴离子与三聚氰胺阳离子反应产物的紫外-可见光谱特性。实验发现,加入三聚氰胺后,体系λmax由426nm红移到516nm,加入SDS对缔合物有显著的增稳、增敏效应。三聚氰胺质量浓度在1.9～25mg/L范围内符合比尔定律,缔合物的表观摩尔吸光系数为6.9×103L.mol-1.cm-1。本方法用于液态奶及奶粉中三聚氰胺的测定,回收率分别为94.5%～104.8%和95.5%～100.4%,相对标准偏差分别为1.6%～2.2%和1.7%～2.6%。考察了酸效应、胶束对体系的作用机理,发现三聚氰胺与AR缔合物之间主要是通过静电引力和疏水作用力相结合。     

荧光法快速检测有机磷农药残留总量

在pH4.60的B-R缓冲溶液中,中性红(NR)与一定浓度的十二烷基苯磺酸钠(SDBS)发生荧光增强反应,在该体系中加入有机磷农药后,在激发波长560 nm,发射波长604 nm处体系的荧光强度明显降低,且降低程度与有机磷农药的加入量呈良好的线性关系,其线性范围和检出限分别为0.024~0.40 mg/L,0.014 mg/L。据此建立了测定有机磷农药残留总量的新方法。方法已用于面粉和土壤中有机磷农药残留总量的检测,回收率在92.0%~100.5%之间,RSD在1.1~1.9%之间。     

单纵模671nm红光激光器

利用全波片和Nd:YVO4激光器的偏振特性构成双折射滤光片,使用I类临界相位匹配LBO作为倍频晶体,在注入泵浦功率2.7W的情况下获得149mW的671nm单纵模红光输出,光-光转换率5.6%,该结构简单、紧凑,适合用于中低功率激光器。     

基于相变原理模拟红色顶发射有机电致发光器件的出光性能

研究了有机发光器件(organic light emitting diodes, 简记为OLED)半透明电极上形成的反射相移对OLED光谱产生调制现象.以红色微腔结构顶发射OLED(top emitting OLED,TOLED)为例,基于微腔理论和传输矩阵理论建立物理模型,采用计算机数值模拟方法,得出结果表明器件发光光谱的调制作用不只局限于有机层厚度,也和反射相移有关.通过改变覆盖到顶电极表面的有机层厚度的简单方法,可以实现对顶电极反射相移的调节,从而改变TOLED光学性能.这一结果为进一步改善器件的性 关键词： 反射相移模拟 红色微腔 顶发射有机发光     

气相色谱－质谱法测定赤鳞鱼肉中的脂肪酸

利用气相色谱质谱（ＧＣ／ＭＳ）电子轰击方法，对６种不同年龄和不同性别的赤鳞鱼肉中的饱和、不饱和脂肪酸（经甲酯化后）进行了测定，用色谱法作了定量，共鉴定出１８种脂肪酸。     

Ag离子注入非晶SiO2的光学吸收、拉曼谱和透射电镜研究

能量为200keV的Ag离子，以1×10¹⁶，5×10¹⁶，1×10¹⁷ cm^-2的剂量分别注入到非晶SiO₂玻璃，光学吸收谱显示：注入剂量为1×10¹⁶ cm^-2的样品的光吸收谱为洛伦兹曲线，与Mie理论模拟的曲线形状一致；注入剂量较大的5×10¹⁶，1×10¹⁷ cm^-2的谱线共振吸收增强，峰位红移并出现伴峰. 透射电镜观察分析表明，注入剂量不同的样品中形成的纳米颗粒的大小、形状、分布都不同，注入剂量较大的还会产生明显的表面溅射效应，这些因素都会影响共振吸收的峰形、峰位和峰强. 当注入剂量达到1×10¹⁷ cm^-2时，Ag纳米颗粒内部可能还形成了杂质团簇. 关键词： 离子注入 纳米颗粒 共振吸收 红移