一种氮掺杂的石墨烯量子点的制备及其光催化性能研究

石墨烯量子点是石墨烯中一种新型的碳基零维纳米材料,除了具备石墨烯本身的物理化学性质之外,同时拥有良好的生物相容性、稳定性、低毒性、光致发光等特性。报导了一种以多壁碳纳米管(MWCNTs)为碳源,通过改良的Hummers法氧化剥离制备石墨烯量子点(GQDs)的简单方法,所得到的GQDs样品具有很强的光电子性能。作为一种有效的增效剂,通过简单的湿浸渍法和肼还原法成功的合成了P25-R-GOQDs-N纳米复合材料。在可见光照射下,对有机染料罗丹明B(Rh B)进行光催化降解实验,相比于P25(商业化Ti O2),P25-R-GOQDs-N样品显示出更高的光催化活性,表明石墨烯量子点起到了关键作用。     

荧光探针用于食品添加剂定量分析的实验设计

为了让学生掌握荧光分光光度计的使用方法,了解如何采用荧光传感器对食品添加剂进行定量分析,设计了一个研究型的综合实验。基于食品添加剂胭脂红对石墨烯量子点（GQDs）的荧光猝灭作用,在考察溶液酸度和孵育时间对猝灭反应影响的基础上,建立胭脂红浓度与石墨烯量子点荧光强度变化的关系曲线,并对购得的饮料溶液中胭脂红含量进行了定量分析。在实验过程中引入机理讨论,不仅能拓宽学生的知识面,而且能提高学生解决实际问题的能力。本实验集科研性和趣味性于一体,使学生体会到科研的乐趣,激发学生的学习兴趣。该实验操作简单、易行,适用于本科生的综合实验能力训练。     

亮蓝与石墨烯/CdTe量子点复合物相互作用的荧光光谱性能研究

成功地合成了石墨烯/CdTe量子点复合物,并基于亮蓝对石墨烯/CdTe量子点复合物的较强的荧光猝灭作用,研究了亮蓝与石墨烯/CdTe量子点复合物相互作用的光谱性能。研究发现,亮蓝的紫外吸收光谱和石墨烯/CdTe量子点复合物的荧光发射光谱相互重叠,亮蓝荧光发射强度的增加和石墨烯/CdTe量子点复合物荧光发射强度的降低,推断两者之间发生了荧光共振能量转移。此外,石墨烯/CdTe量子点复合物荧光强度的降低（F₀/F）与亮蓝的浓度之间具有良好的线性关系,线性范围为12.62-94.65nmol·L^-1,最低检出限为6.4nmol·L^-1,可用于溶液中亮蓝的定量分析,为建立新型荧光传感器提供了理论和实验基础。     

Preparation of Magnetic Fluorescent Dual-drug Nanocomposites for Codelivery of Kaempferol and Paclitaxel

Magnetic fluorescent dual-drug nanocomposites(MFDDs) were developed with the aim of simultaneouly delivering two different anticancer drugs, kaempferol(KAE) and paclitaxel(PTX). Firstly, Fe_3O_4/bovine serum albumin(Fe_3O_4/BSA) composite microspheres with physically entrapped KAE were prepared, then microspheres were modified with PTX/graphene quantum dots(PTX/GQDs) through chemically bonding, and the MFDDs were obtained. The properties of nancomposites were characterized by X-ray diffractometry, Fourier-transform infrared spectroscopy, transmission electron microscopy, vibrating sample magnetometry and X-ray fluorescence spectrometry. It was found that the superparamagnetic nanocomposites had ultrafine size(below 110 nm), high saturation magnetization of 24.36 emu/g, and significant fluorescence. Furthermore, the cumulative in vitro release of the MFDDs exhibited controlled drug release. Cell viability experiments confirmed that the co-administration of KAE with PTX had a superior cytotoxicity to the Hela cells compared with single drug-loaded forms. Therefore, dual anticancer drug-loaded MFDDs have the potential to be used for cancer combined chemotherapy.     

Novel Formaldehyde Sensor based on Hydrogen Peroxide/Melamine Modulated Photoluminescence of Nitrogen-doped Graphene Quantum Dots

A modulated photoluminescence nanosensor was developed for the quantitative detection of formaldehyde with nitrogen-doped graphene quantum dots and melamine. The sensing system was based on the different activated effects of melamine and hydrogen peroxide on the photoluminescence intensity of nitrogendoped graphene quantum dots. Under the optimal conditions, the modulated photoluminescence sensing system can be used to detect formaldehyde with a good linear relationship between the nitrogen-doped graphene quantum dots photoluminescence difference and the concentration of formaldehyde. The novel sensing system provided new directions for the detection of formaldehyde with high selectivity and quick response.     

胭脂红和苋菜红与石墨烯/CdTe量子点复合物相互作用的对比研究

分别测定了胭脂红和苋菜红与石墨烯/CdTe量子点复合物相互作用的荧光光谱和紫外吸收光谱。研究发现胭脂红和苋菜红均对石墨烯/CdTe量子点复合物具有较强的荧光猝灭作用,且均为静态猝灭过程。但是由于结构上的差异,所引起的石墨烯/CdTe量子点复合物荧光猝灭率有所不同。通过变温实验、紫外吸收光谱和结构分析,得出胭脂红引起的石墨烯/CdTe量子点复合物的猝灭率更高。研究还发现,胭脂红和苋菜红的浓度与石墨烯/CdTe量子点复合物荧光强度的降低之间均存在良好的线性关系,可分别用于胭脂红和苋菜红的定量分析。     

Carbon quantum dots/BiVO4 composite with enhanced photocatalytic activity

Science China Technological Sciences - In this study, we report the facile fabrication of a carbon quantum dots (CQDs)/BiVO4 composite with efficient photocatalytic activity. Due to the excellent...     

量子磁盘表面磁场分布模拟

量子磁盘由于记录点尺寸很小,用常规的磁场测量方法无法对其表面磁场分布数值图进行测试。为了证实量子磁盘的可行性,该文对量子磁盘表面的磁场分布用有限元软件进行模拟计算,在假设量子磁盘的磁化方向为水平磁化的前提下,得到了圆形量子点直径为20 nm;量子点间距离为10 nm;方形量子点边长为20 nm,间距为20 nm的情况下量子磁盘的二维表面磁场分布图,证实了其表面磁场分布具有明显的周期性,周期长度为量子点大小加上量子点间距离。并且所得到的磁场分布图为量子磁盘的理论研究提供了一定的参考数据。     

CdTe量子点碳糊修饰电极的制备及多巴胺测定

在碳糊中加入CdTe量子点制成修饰电极(CdTe/CPE),并研究了多巴胺(DA)在该修饰电极上的电化学行为.实验结果表明:在pH 7.0 PBS缓冲液中,电极上的CdTe量子点对DA的氧化还原呈现明显的电催化作用,电催化过程为表面吸附控制过程.闭路吸附时间为60s达到饱和,此电极可用于测定DA,响应迅速(1.5 s).峰电流与DA浓度在4×10-4-5×10-5 mol/L范围内呈线性关系,灵敏度高达0.061 9 A·L/mol,检测极限可达1.4 × 10-6mol/L.     

One-pot synthesis of bio-inspired layered materials of 3D graphene network/calcium carbonate

A bio-inspired layered material of reduced graphene oxide (RGOs) and calcium carbonate was synthesized via a one-pot strategy in DMF/H₂O mixed solvent. The experimental results show that the product is a layered material of wrinkled RGOs networks and micron-sized calcium carbonate particles with uniform granular diameter and homogeneous morphology, which are distributed between the layered gallery of the graphene scaffold. The polymorph and the morphology of the in-situ produced calcium carbonate particles can be manipulated by simply changing the temperature scheme. Besides, the graphene oxide was reduced to a certain extent, and the hierarchical wrinkles were generated in the RGOs layer by the in-situ formation of the calcium carbonate particles. This work provides a facile and controllable strategy for synthesizing layered material of RGOs and carbonates, and also presents a platform for making three-dimensional porous wrinkled RGOs networks.     

CdTe量子点荧光猝灭法测定尼群地平的研究

以L-半胱氨酸为稳定剂,在水溶液中合成了CdTe量子点.以该量子点为荧光探针,基于荧光猝灭法对尼群地平进行了定量检测.考察了缓冲体系、缓冲液浓度、缓冲液pH值、反应时间、量子点浓度等多种因素的影响,并对反应机理进行了初步的探讨.在0.03 mol/L、pH值为5.78的Tris-HCl缓冲液中,当量子点浓度为5.72×10^-4mol/L、反应时间为10 min时,该方法的线性范围为0.38-77μg/mL,检出限为0.28μg/mL.该方法已成功用于药片中尼群地平的测定,与中国药典中的标准方法比较,结果满意.     

CdS quantum dots-sensitized TiO2 nanotube arrays for solar cells

CdS quantum dots(QDs) sensitized TiO2 nanotube arrays photoelectrodes were investigated for their photovoltaic performance of quantum dots-sensitized solar cells. The highly ordered TiO2 nanotube arrays(TNAs) were synthesized on Ti foils by anodic oxidation method. Then CdS quantum dots were deposited onto the TiO2 nanotube arrays by successive ionic layer absorption and reaction(SILAR) method to serve as the sensitizers. Cd(NO3)2 and Na2S were used as the precursor materials of Cd+ and S2- ions, respectively. It is found that the CdS QDs sensitizer may significantly increase the light response of TiO2 nanotube arrays. With increasing CdS QDs deposition cycles, the visible light response increases. Maximum photocurrent was obtained for the QDs that have an absorption peak at about 500 nm. Under AM 1.5 G illuminations(100 mW cm-2), a 4.85 mA/cm2 short circuit current density was achieved, and the maximium energy conversion efficiency of the as-prepared CdS QDs-sensitized TNAs solar cells was obtained as high as 0.81 % at five SILAR cycles.     

大氢稀释逐层法制备纳米硅薄膜

如何制备高密度、分布可控、尺寸一致的纳米硅量子点,是各种纳米器件研究中首先需要解决的问题。在等离子体增强化学气相沉积系统（PECVD）中,用大氢稀释逐层淀积技术在氮化硅表面上自组装生长高密度、尺寸均匀的硅量子点结构,这种方法充分利用了氢气等离子体在薄膜淀积中诱导晶化作用和对非晶结构的选择刻蚀作用,能够在低衬底温度的条件...     

一种应用比率荧光法定量分析水体中亚甲基蓝含量的方法

亚甲基蓝作为一种染料,被广泛用于工业、医药、水产养殖和皮肤护理等领域。但是过量使用亚甲基蓝,不仅污染环境,还会危害人类和动物的健康。 通过将石墨烯量子点与CdTe量子点混合得到比率荧光检测体系,依据荧光强度变化和亚甲基蓝浓度之间的线性关系,建立了一种定量分析亚甲基蓝含量的方法,线性范围为3.13 - 9.38 nmol/L,最低检出限为0.5589 nmol/L。该方法具有较高的灵敏性、选择性与稳定性,可用于检测水溶液中亚甲基蓝含量。     

CdTe量子点与盐酸克伦特罗的相互作用研究

通过水热法合成CdTe量子点,基于盐酸克伦特罗与CdTe量子点之间的相互作用,建立了一种盐酸克仑特罗的定量分析方法。研究发现盐酸克伦特罗对CdTe量子点具有荧光增强作用,且荧光强度的升高（F/F₀）与盐酸克伦特罗浓度之间具有良好的线性关系,回归方程为F/F₀=0.3970C_clenbuterol+1.024,检出限为0.3402 nmol·L^-1,该方法为研发通过荧光方法对盐酸克伦特罗进行定量分析提供了实验依据。     

CdTe/CdS核/壳结构纳米晶量子点的结构及荧光性能

采用水相合成法,制备出核/壳结构CdTe/CdS纳米晶量子点,用红外光谱和X射线衍射对其结构进行了表征,并对CdTe纳米晶量子点光稳定性以及CdTe/CdS纳米晶量子点荧光特性影响因素进行了研究.结果表明:随着放置时间的增加,CdTe量子点的光学稳定性下降;随着反应时间的增加和壳/核比例的增加,CdTe/CdS纳米晶量子点的荧光发射波长均发生红移;且反应时间增加,荧光强度增强;当CdS与CdTe壳/核比例为2∶1时,荧光强度最强.     

生物功能化AgInS_2量子点的制备及其生物应用

为制备水相、低毒、生物兼容性较好的三元量子点,通过水相合成法制备三元银铟硫(AgInS_2)量子点,并用叶酸(FA)对其进行修饰,利用透射电子显微镜、紫外-可见-近红外分光光度计、荧光分光光度计、傅里叶红外光谱仪等表征手段对纳米复合材料的形貌、光学性质、化学组成、细胞毒性及荧光成像进行了研究。结果表明,水相AgInS_2量子点的尺寸约为5nm~6nm,经叶酸(FA)修饰后,细胞毒性较低,在乳腺癌细胞中成像时红色荧光更明显,说明通过叶酸的修饰可提高量子点的生物兼容性。因此这类具有较好水溶性和生物兼容性的FA-AgInS_2量子点可直接应用于生物成像研究,为乳腺癌的快速体外检测打下了良好的实验基础。     

量子点制备及应用进展

量子点是一种具有独特光电性质的新型荧光纳米材料,以高增益、低噪声和高功率放大等优点引起了广泛的关注与应用.本文以量子点的结构和主要特性为核心,概述量子点的制备方法及表面修饰的意义,简述量子点在生命科学、农业检测、光电子、环境科学等领域的研究及应用进展.     

Alcohol Solvent Effect on Fluorescence Properties in the Solvothermal Synthesis of Carbon Quantum Dots

Highly monodisperse carbon quantum dots (CQDs) were synthesized by a solvothermal method using L-ascorbic acid as carbon source and different simple alcohols (methanol,ethanol,ethylene glycol,and isopropanol) as reaction solvents at 180 ℃ for 4 hours.The performance of CQDs was characterized by transmission electron microscope (TEM),Fourier infrared spectrometer (FTIR),UV-visible spectrophotometer,and fluorescence spectrophotometer.The results show that the prepared CQDs are wavelength-dependent...     

量子点与金属纳米线耦合系统中表面等离子激元的散射特性

利用由1根金属纳米线与2个相互耦合的量子点构成的系统研究了金属纳米线中单个表面等离子激元的传输特性.研究结果表明,通过适当地调节2个量子点的损耗率、量子点与金属纳米线之间的耦合强度、 2个量子点之间的相位和耦合强度能在异常点处获得单向无反射.该方案可为类二极管等非互易器件的研发提供理论参考.