基于酶剪切量子点荧光放大技术的双元miRNA定量检测

将量子点荧光特性与双链特异性核酸酶的DNA剪切特性相结合,提出一种高灵敏度、高特异性的双元miRNA定量检测方案.首先,将量子点和四氧化三铁磁性纳米粒子分别与捕获DNA链接形成捕获探针,再与待测miRNA互补配对形成异源双链杂合结构,随后双链特异性核酸酶对杂合结构中的捕获DNA进行特异性剪切,实现量子点和待测miRNA从捕获探针分离,且分离的待测miRNA与捕获探针上未配对的DNA开始新一轮杂交和再剪切.经过上述循环过程,量子点从捕获探针大量释放,荧光信号不断增强,实现肿瘤标志物miRNA的高灵敏检测.实验结果表明,基于酶剪切量子点荧光放大技术,在1fmol/L至100pmol/L的浓度范围内,同时实现了肿瘤标志物miRNA-141及循环miRNA内参miRNA-1228的特异性定量检测,其检出限分别达到0.69fmol/L和0.21fmol/L.与实时荧光定量多聚核苷酸链式反应方法相比,该方案获得了相同的检测结果,且具有更高灵敏度.     

Optical tape for high capacity three-dimensional optical data storage

In this Letter,a new approach of optical tape for high capacity multilayer data storage is proposed.We show that a length of 5 cm and width of 2 cm of soft and transparent optical tape can be used for two-photon three-dimensional bit data storage.We successfully demonstrate writing and reading of six layers of data storage with a transverse bit separation of 2μm and an axial separation of 2.5μm in a tetraphenylethylene-doped photobleaching polymer.The fluorescence intensity is insensitive to the storage depth of the photopolymer matrix.Thus,the optical tape that we put forward in the experiment can help people realize true large data storage in the future,like magnetic tape.This method significantly paves a novel way for solving big data storage problems.     

Fractional density of states and the overall spontaneous emission control ability of a three-dimensional photonic crystal

Fractional density of states(FDOS) hinders the accurate measuring of the overall spontaneous emission(SE)control ability of a three-dimensional(3 D) photonic crystal(PC) with the current widely used SE decay lifetime measurement systems. Based on analyzing the FDOS property of a 3 D PC from theory and simulation,the excitation focal spot position averaged FDOS with a distribution broadening parameter was proposed to accurately reflect the overall SE control ability of the 3 D PC. Experimental work was done to confirm that our proposal is effective, which can contribute to comprehensively characterizing the SE control performance of photonic devices with quantified parameters.     

两种双光束超分辨数据写入机理的比较

比较了基于光激发-光抑制(SPIN)和受激辐射损耗(STED)的两种双光束超分辨数据写入技术的机理,为基于STED的超分辨数据写入技术建立了动态物理模型,研究其光致聚合过程中的工作机制,并模拟了基于SPIN和STED的双光束超分辨数据写入技术在记录点尺寸和分辨率方面的差异。结果表明:基于STED的双光束超分辨数据写入技术具有无需抑制剂、原理简单的优势,但其需要第二束辅助光的强度较大且对聚合作用的抑制效率低,在多点写入情况下点的尺寸变大,记录均匀性变差。基于SPIN的双光束超分辨数据写入技术所需能量小,多点记录时引发剂分子消耗将抵消抑制剂分子消耗带来的影响,整体均匀性和稳定性好。因此基于SPIN的双光束超分辨数据写入技术在超高密度存储领域应用前景更好。     

Tm3+/Yb3+共掺氟氧硅铝酸盐玻璃陶瓷蓝色上转换发光研究

按摩尔百分比制备了组分为30SiO₂-(20-x-y)Al₂O₃-40PbF₂-10CdF₂-xTm₂O₃-yYb₂O₃的两组Tm³⁺/Yb³⁺共掺杂氟氧硅铝酸盐上转换蓝色发光玻璃陶瓷材料,测量了其在980nm激 关键词： 玻璃陶瓷 上转换发光 3+/Yb³⁺掺杂')" href="#">Tm³⁺/Yb³⁺掺杂 掺杂浓度     

Tm3+/Yb3+共掺氟氧硅铝酸盐玻璃陶瓷蓝色上转换发光研究

按摩尔百分比制备了组分为30S102.(20-x-y)Al2O3-4OPbF2-1OCdF2-xTm2O3-yYb2O3的两组Tm3 ,Yb3 共掺杂氟氧硅铝酸盐上转换蓝色发光玻璃陶瓷材料,测量了其在980nm激光激发下的上转换发光光谱,分析了此材料中Tm3 /YI)3 发光体系的上转换发光机理,并系统地研究了Tm3 离子和Yb3 离子的浓度对该材料上转换发光性能的影响.研究表明:由于Tm3 离子之间存在着交叉弛豫作用使得蓝光(477nm)发光强度随Tm3 离子浓度增加而减弱,实验获得的最佳掺杂浓度为x=0.025(mol%);另外,在Tm3 /Yb3 上转换发光体系中,Yb3 离子合作上转换能量传递过程和三光子过程是共同存在的,随着yb3 离子浓度的增加,Tm3 离子3H4能级到Yb3 离子2F5/2能级的反向能量传递增强使3H4能级上粒子布居数不断减少,三光子过程作用减弱;但是Yb3 离子合作上转换能量传递过程则发挥越来越大的作用,使上转换蓝光强度总体上不断增加.