将功能纳米材料发展前沿融入实验教学——隐形荧光墨水的制备

为了让学生了解纳米材料的性质和用途，开发了一个研究型综合性实验——隐形荧光墨水的制备。通过微波反应快速地制备了一种新型的氮掺杂碳量子点，克服了碳量子点制备繁琐的难题，使碳点的制备能够在实验教学中得以实现，利用透射电镜、X射线衍射、红外光谱以及X射线能谱对碳点的结构和形貌进行表征，利用紫外-可见-近红外光谱仪和荧光光谱仪研究碳点的稳定性和光化学性能；并将该碳点制作成隐形荧光墨水，增加了实验的趣味性和实用性。学生实验证明该综合性实验适用于本科生实验教学。     

引入前沿科学 培养化学核心素养——以“碳量子点的制备”综合实验设计为例

为培养化学核心素养,让中学生了解前沿科学领域明星材料纳米材料的性质和用途,设计开发了一个基于中学生认知水平的研究型综合实验--碳量子点的制备。以含碳量丰富的生物质材料为原料,通过碳化反应以及多次过滤处理方法制备了一种新型的碳量子点,克服了碳量子点制备所需的高温高压等条件限制,使碳量子点这一新型纳米材料的制备能够在中学化学实验中得以实现,利用荧光灯对碳量子点的荧光性质进行定性表征,并将碳量子点制作成隐形荧光墨水,增加了实验的趣味性和实用性。学生实验证明该综合实验适用于中学化学实验教学和实验能力培养,有助于培养学生的科学探究精神、创新意识和社会责任感。     

研究型综合化学实验设计:碳量子点的制备及其在叶酸检测中的应用

以高校创新型人才培养为目标,设计了一个研究型综合化学实验。以柠檬酸和尿素为原料,通过水热法制备了发射强烈蓝色荧光的碳量子点,表征了其紫外-可见吸收光谱和荧光光谱,进一步研究了该碳量子点在叶酸的检测中的应用。本实验涉及纳米材料制备、表征及应用相关知识,适合作为高年级本科生的研究型综合化学实验,有助于激发学生的研究兴趣和培养学生的科研思维。     

川木香水热法一步合成荧光碳量子点及光学性能研究

以中药材川木香原药为碳源，采用水热法一步合成了荧光碳量子点。通过水热法实验条件优化，获得制备荧光碳量子点的最佳实验参数，通过透射电镜(TEM)对荧光碳量子点进行形貌表征，通过X射线光电子能谱分仪(XPS)对荧光碳量子点进行元素组成分析，通过荧光光谱和紫外-可见吸收光谱对荧光碳量子点进行了光学性能研究。结果表明：川木香用量1.00 g,水热反应温度180℃,水热反应时间2.0 h时，制备得到的荧光碳量子点光学性能最佳。荧光碳量子点平均粒径为5 nm,主要含有C元素和O元素，最大激发波长为360 nm,对应的发射波长为420 nm,特征吸收峰为280 nm,量子产率为12.9%。     

荧光碳点的制备及其荧光特性的研究和应用

围绕具有优良荧光发光特性的无机纳米材料——碳点,设计一个本科化学实验。通过"自下而上"的方法分别制备蓝色、绿色荧光碳点溶液;考察荧光碳点溶液的荧光激发和发射光谱关系,相对法测定荧光量子产率;探究不同浓度和pH条件下的荧光光谱变化;并将荧光碳点应用到防伪技术领域,加深学生对荧光材料的相关荧光概念和表征手段如荧光激发光谱、荧光发射光谱、荧光量子产率,术语如Stokes位移和荧光影响因素等理论知识的理解,同时通过防伪应用开拓学生的思维,鼓励学生将课堂所学应用到实际生产生活中。     

碳量子点的有效掺杂及其在TNP检测中的应用

以葡萄糖为碳源,半胱氨酸盐酸盐为氮、硫共掺杂剂,分别采用热解法和水热法制备了两种氮、硫共掺杂的碳量子点(N,S-CDs),并比较了用这两种方法制备碳量子点的荧光性能及其对2,4,6-三硝基苯酚的荧光响应。结果表明,与水热法制备的碳量子点(H-CDs)相比,由热解法制备的碳量子点(T-CDs)具有更高的荧光量子产率和更长的荧光发射波长,对TNP的响应具有更高的选择性。因此,基于T-CDs构建TNP的荧光传感体系,该方法对TNP检测的线性范围为0.05～50μM,检出限为18.85 nM。此外,将该荧光探针用于水样中TNP的检测,加标回收率为97.82%～114.50%,表明该探针可用于实际水样品中TNP的检测。     

葡萄糖酸碳量子点的合成及其光学性能的研究

以葡萄糖酸为碳源,采用微波法、热解法和水热溶液法合成了水溶性较好的蓝色荧光碳量子点。用透射电镜(TEM)观察其形貌,荧光光谱(FL)和紫外可见光谱(UV)探究其激发和发射光谱,用时间分辨光谱(TRF)测其荧光寿命值。微波和热解法制备的碳量子点粒径在2.5~7.5 nm之间,激发波长为360 nm,发射波长为450 nm,荧光发射依赖激发波长,有三个荧光寿命,表面状态不均一。水热法制备的碳量子点,粒径在3.0~8.5 nm之间,激发波长为350 nm,发射波长为430 nm,荧光发射不依赖激发波长,只有一个荧光寿命值,表面状态均一。水热法合成的碳量子点荧光量子产率高为6.01%,为进一步研究葡萄糖酸制备碳量子点提供参考。     

掺氮高荧光碳点的一步法制备及对痕量Hg(Ⅱ)离子的选择性检测

采用一步水热法制备了一种水溶性的、具有良好荧光性能的掺氮碳量子点(N-碳点),其尺寸大小均匀,约为7 nm。N-碳点的荧光强度随N的掺杂量、水热反应温度、溶液的p H值而改变。在最佳反应条件下所制备的N-碳点的荧光量子产率高达24.4%。该N-碳点作为一种简单、低成本的荧光探针用于检测痕量Hg2+,具有高选择性和高灵敏度的特点,其最低检测极限可达到0.02μmol·L-1(4.012 ng)。     

功能高分子材料综合实验设计:荧光稀土液晶高分子防伪膜的制备

设计了一个综合性实验,将荧光稀土液晶高分子防伪膜的制备和现代分析测试技术应用于高分子专业的教学实验中,以提高学生的综合实践能力。实验包括荧光稀土液晶高分子的制备、表征、防伪性能评价3大部分。采用FTIR、荧光光谱仪、POM、XRD、TG表征荧光稀土液晶高分子的结构与性能;制备荧光稀土液晶高分子防伪膜对其防伪性能进行评价,给整个实验增添趣味性与实用性。通过开设该实验,可让学生了解功能高分子的前沿知识及现代分析测试技术的基本原理和用途,掌握专业的实验操作与数据处理方法,提高学生的综合实践能力和专业素质。学生实验证明该综合实验适用于本科实验教学。     

碳点的制备及在荧光分析中的应用

综述了碳点的制备方法、碳源材料以及碳点在荧光分析中的应用(包括生物成像、生物分子检测和金属离子检测)。碳点的合成方法包括自上而下法(电弧放电法、激光消融法、电化学合成法和酸氧化法)及自下而上法(微波法、水热法和超声法),并对碳点的发展前景进行了展望(引用文献79篇)。     

溶剂化的热力学集团展开理论

把二元溶液的过剩内能（excess energy）分成溶剂-溶剂、溶剂-溶质及溶质-溶质相互作用部分。利用集团展开方法给出了二元溶液在正则系综的配分函数的表达式,利用该表达式得到了溶质的偏摩尔内能(partial molar energy)和偏摩尔熵(partial molar entropy)的表达式。在无限稀溶液情形,过剩偏摩尔内能的溶剂-溶剂部分又称重组织内能（reorganization energy）,它反映了溶质存在时对其周围溶剂分子之间的相互作用能的影响。研究表明,在溶质的粒子数密度相对较大时,溶质分子之间的相互作用将影响过剩偏摩尔内能的溶剂-溶剂部分,对于稀溶液,过剩偏摩尔内能的溶剂-溶剂部分与溶质的摩尔分数成线性关系。对低密度二元溶液,溶质的过剩偏摩尔内能和过剩偏摩尔熵也与溶质的摩尔分数成线性关系。     

Polymeric Lids for Microcontainers for Oral Protein Delivery

Oral delivery of proteins and peptides is one of the main challenges in pharmaceutical drug development. Microdevices have the possibility to protect the therapeutics until release is desired, avoiding losses by degradation. One type of microdevice is polymeric microcontainers. In this study, lysozyme is chosen as model protein and loaded into microcontainers with the permeation enhancer sodium decanoate (C10). The loaded microcontainers are sealed and functionalized by applying polymeric lids onto the cavity of the devices. The first lid is poly(lactic‐co‐glycolic) acid (PLGA) and on top of this either polyethylene glycol (PEG) or chitosan is applied (PLGA+PEG or PLGA+chitosan, respectively). The functionalization is evaluated in vitro for morphology, drug release, and mucoadhesive properties. These are coupled with in vitro and ex vivo studies using Caco‐2 cells, Caco‐2/HT29‐MTX‐E12 co‐cultures, and porcine intestinal tissue. PLGA+chitosan shows slower release compared to PLGA+PEG or only PLGA in buffer and the transport of lysozyme across cell cultures is not enhanced compared to the bulk powder. Microcontainers coated with chitosan or PEG demonstrate a three times stronger adhesion during ex vivo mucoadhesion studies compared to samples without coatings. Altogether, functionalized microcontainers with mucoadhesive properties and tunable release for oral protein delivery are developed and characterized.     

Bump-hunting for the proficiency tester--searching for multimodality

Kernel density estimation is a method for producing a smooth density approximation to a dataset and avoiding some of the problems associated with histograms. If it is used with a degree of smoothing determined by a fitness for purpose criterion, it can be applied to proficiency test data in order to test for multimodality in the z-scores. The bootstrap is an essential additional technique to determine how rugged the initially estimated kernel density is: the random resampling of the data in the bootstrap simulates a complete blind repeat of the proficiency test. In addition, useful estimates of the standard error of a mode can be thus obtained. It is suggested that a mode and its standard error can be used as an assigned value and its standard uncertainty.     

Wetting for self-healing and electrowetting for additive manufacturing

Advanced additive manufacturing actively widens its tool box of wettability-related phenomena to be used in production of new items. Novel self-healing engineering materials incorporate vascular networks with two types of nanochannels: the one containing a resin monomer, whereas another one — a curing agent. If such nanocomposites are damaged locally, both types of channels are locally broken, and they release resin monomer and curing agent droplets. These droplets spread by wettability over the nanotextured matrix, touch each other, and coalesce, which triggers polymerization reaction and crack stitching. Wettability-facilitated droplet spreading is accompanied by liquid imbibition in the pores in the nanofiber network. Such process peculiarities are in focus in the present review. An additional process relevant in direct writing and 3D printing is electrowetting (EW). It stems from the change in the contact angle in response to the electric polarization of dielectric substrates. EW allows movement of droplets on horizontal, vertical, and inverse surfaces, which can significantly facilitate the existing direct writing and 3D printing technologies. Accordingly, EW is also in focus in the present review.     

Call for nominations for the Heinrich-Emanuel-Merck Award

News and Announcements

Call for nominations for the Heinrich-Emanuel-Merck Award     

Advances for proficiency testing for genetic laboratory science

Nucleic acid based clinical genetic testing has undergone explosive growth in recent years due in large part to the human genome project. Characterization of the human genome has led to a molecular understanding of the pathogenesis of many human diseases, and ultimately to clinical molecular tests becoming routinely used to diagnose a wide diversity of diseases. This rapid growth in clinical molecular genetic testing coupled with the complexity of the analytical procedures underscores the necessity for proficiency testing (i.e. external quality assessment) to allow laboratories offering such services the ability to evaluate their analytical procedures via inter-laboratory comparisons. The American College of Medical Genetics (ACMG) in partnership with the College of American Pathologists (CAP) have been offering proficiency testing for clinical molecular genetics laboratories since 1995, and presently have more than 230 laboratories from 11 countries enrolled in this program. This paper describes the evolution of this program and several challenges encountered in the delivery of a proficiency testing program for laboratories offering clinical molecular genetic services. Received: 13 April 2002 Accepted: 18 July 2002     

A methodology for choosing parameters for ESR readout of alanine dosimeters for radiotherapy

Spectrometer settings for ESR readout of alanine dosimeters for radiotherapy have been investigated. Several ESR parameters were studied and determined. The main reason for this work is to choose the suitable parameters to increase signal-to-noise ratio and to reduce the uncertainty on ESR readout, which is one of the main components of uncertainty of alanine/ESR dosimetry system for radiotherapy. The new spectrometer settings have been applied for ESR readout of alanine dosimeters irradiated from 1 to 10 Gy. A higher signal-to-noise ratio has been achieved compared to our old spectrometer settings. The extended uncertainty (k=2) has been evaluated in the dose range 2–10 Gy (maximum uncertainty of 4.9% for 2 Gy, while minimum uncertainty of 1.4% for 10 Gy), which implies that the alanine/ESR dosimetry system can be applied to radiotherapy dose level that needs a global accuracy of 5%.