【期刊专栏】《分析化学》2020年第6期英文版正式发布

分析化学蔻享学术

1589868018(1).png Progress in Analysis of Tau Protein

LI Lin-Yu, WANG Xiao-Ying*

Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health,Southeast University,Nanjing 210009,China

Highlights

Tau蛋白(简称Tau)是一种参与神经系统发育的微管相关蛋白。Tau可经历构象改变、异常mRNA剪接等,从微管解离,经系列翻译后修饰(Post-translational modification,PTM),自身形成病理性聚集,进而造成神经退行性病变,最终形成Tau病。研究Tau的病理过程,分析评估其PTM及定量检测其浓度变化,对Tau病的早期诊断、跟踪、预防和治疗具有重要意义。本文对目前Tau的常规分析方法进行了概述和比较,重点阐述光学、电化学生物传感方法的最新研究进展与相关应用,对未来发展方向进行了展望,为Tau 蛋白的深入研究与应用提供参考。

Abstract

Tau protein, simply referred to as Tau, is a type of microtubule-associated protein involved in the development of nervous system. After experiencing conformational changes, abnormal mRNA splicing, etc., Tau dissociates from microtubules and undergoes a series of post-translational modification (PTM) to form pathological aggregation, which induces neurodegenerative diseases and tauopathies eventually. Numerous clinical studies suggest that it is of great significance for the early diagnosis, tracking, prevention and treatment of tauopathies by studying the pathological process of Tau protein, analyzing and evaluating its PTM and quantitative detection of concentration changes. In this paper, the conventional analysis methods for Tau protein at home and abroad were summarized and compared. Specifically, the related applications and latest research progresses of optical and electrochemical biosensors were mainly described. Furthermore, the summary of its future directions and the potential applications were proposed, which provided reference for the further research and application.

Graphical Abstract

Tau is a microtubule-associated protein involved in the development of nervous system. Researches including pathological process of Tau, series of PTM and concentration changes are significant for the early prevention and treatment of Tau disease. This article summarizes the current convention alanalysis methods for Tau and the latest research progress in optical and electrochemical biosensors.

1589505057(1).jpg

Paper-supported Co-culture System for Investigation of Exosomes Mediated Interactions between Breast Cancer Cells and Lung Fibroblasts

LIN Zhun¹,CHEN Xiao¹, LIN Dong-Guo¹, LIU Da-Yu^1,2,3,*

¹Department of Laboratory Medicine, Guangzhou First People's Hospital, School of Medicine, South China University of Technology, Guangzhou 510180, China

²Guangdong Engineering Technology Research Center of Microfluidic Chip Medical Diagnosis, Guangzhou 510180,China

³Clinical Molecular Medicine and Molecular Diagnosis Key Laboratory of Guangdong Province, Guangzhou 510180,China

Highlights

采用多层纸芯片共培养体系研究了外泌体介导的乳腺癌细胞鄄肺成纤维细胞相互作用。多层纸芯片体系包含接种乳腺癌细胞成份的肿瘤层,接种肺成纤维细胞的招募层,以及上述两层之间的侵袭层。叠加多层纸芯片形成包含乳腺癌细胞和肺成纤维细胞的三维共培养体系,而拆解多层纸芯片则逐层检测细胞,因而可以从时间和空间角度解析细胞间相互作用。研究了在肿瘤层接种乳腺癌细胞或固定乳腺癌细胞来源的外泌体,发现二者同样可以诱导招募层的肺成纤维细胞转化为肿瘤相关成纤维细胞。之后,在招募层种植外泌体诱导的肿瘤相关成纤维细胞,其显示出较原生细胞更强的乳腺癌细胞招募作用。研究结果表明,转移前微环境的形成主要在于肿瘤外泌体介导的宿主器官成纤维细胞转化,而宿主器官微环境的改变反之招募肿瘤细胞定向迁移。

Abstract

A multi-layer paper supported co-culturesystem was developed for investigation of the interactions between breast cancer cells and lung fibroblasts mediatedby exosomes. Within the multi-layer structure, the tumor layer and the recruitment layer were impregnated with breast cancer cells and lung fibroblasts respectively, and these two layers were separated by the invasion layers. The co-culture device was constructed by assembling multiple layers of paper.Disassembling such a device enabled cells on each layer to be analyzed individually, which was used to study cell interactions from both time and space aspects. The impregnation of either breast cancer cells or the breast cancer cells derived exosomes on the tumor layer resulted in the conversion of lung fibroblasts on the recruitment layer into cancer-associated fibroblasts.The cancer-associated fibroblasts induced by exosomes were thereafter seeded on the recruitment layer, which showed stronger breast cancer cell recruitment than primary cells. These results suggest that the conversion of host-organ fibroblasts mediated by tumor exosomes is essential for the formation of pre-metastasisniche, and the pre-metastasis niche, in turn, recruits tumor cells to achieve organotropic metastasis.

Graphical Abstract

A multi-layer paper supported co-culture system was developed for investigation of exosomes mediated interactions between breast cancer cells and lung fibroblasts from both temporal and spatial aspects.

Determination of Volatile Metabolites in Microcystis Aeruginosa Using Headspace-Solid Phase Microextraction Arrow Combined with Gas Chromatography-Mass Spectrometry

YU Rui-Peng^1,², WANG Li-Ping², ZHAO Chen-Kai¹,WU Sheng-Fang², SONG Qi-Jun¹,^*

¹School of Chemical and Material Engineering, Jiangnan University,Wuxi 214122,China

²State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122,China

Highlights

建立了顶空-固相微萃取箭型-气相色谱-质谱(HS-SPME Arrow-GC-MS)联用技术,结合多变量统计分析铜绿微囊藻在模拟自然环境条件下,其挥发性代谢物组成及变化规律。通过选取合适萃取头,对不同时期铜绿微囊藻样品中挥发性代谢物进行定性分析,鉴定了210种挥发性代谢物。采用多变量统计分析方法,进一步研究铜绿微囊藻生长过程中挥发性代谢物的消长变化规律,筛选出10种统计学显著性差异代谢物:环己醇、二甲基三硫、苯甲醇、樟脑、2-甲氧基苯酚、3-己烯-1-醇、2, 4-癸二烯醛、吲哚、柠檬醛和正壬醇。优化了萃取温度、萃取时间、体系盐度等SPME Arrow 萃取条件,筛选出差异性代谢物的特征离子峰,并进行定量分析和方法学验证。结果表明,10种统计学显著性差异代谢物在0.050~1000ng/L范围内具有良好的线性关系,相关系数>0.998,检出限范围为0.010~0.030ng/L,回收率在76.3%~93.0%之间,RSD≤12.7%(n=6)。本方法操作简便、快速,灵敏度高,稳定性好,可用于蓝藻水华爆发初期天然水体中挥发性代谢标志物测定。

Abstract

A novel headspace solid phase microextraction arrow (HS-SPME Arrow) method combined with gas chromatography-mass spectrometry (GC-MS) was developed for extraction and analysis of volatile organic compounds of Microcystis aeruginosa under simulated natural conditions. By selecting suitable extraction fibers, 210 kinds of volatile metabolites were identified by full scanning qualitative analysis from the samples of Microcystis aeruginosa in producing period. The metabolic changes of volatile molecules during the growth of Microcystis aeruginosa were analyzed by multivariate statistical analysis and clustering analysis. Chemometric analysis based on principal component analysis, partial least squares-discriminant analysis and heat map associated with hierarchical cluster analysis provided a suitable tool to differentiate volatile organic compounds in algal material. Also 10 metabolites with statistical significance were identified, including cyclohexanol, dimethyl trisulfide, benzenemethanol, camphor, 2-methoxyphenol, 3-hexene-1-ol, 2,4-decadienal, indole, citral and 1-nonanol. Parameters affecting the extraction, such as extraction temperature, time and salt contents were systematically evaluated. The analytical conditions, including desorption temperature and time as well as gas chromatographic parameters, were also optimized. The calibration curves showed a good linearity (correlation coefficient > 0.998) in the concentration range of 0.050–1000 ng/L. The detection limits of this method were 0.010–0.030 ng/L, and the recoveries at the concentration level of 100 ng/L were 76.3%–93.0%. The new method exhibited good precision, with the RSDs values of less than 12.7%. Furthermore, the method also had many advantages such as simplicity, rapidness and applicability to complex matrices, and hence it was suitable to the determination of volatile metabolites in natural water at the early stage of blue-green algae bloom.

Graphical Abstract

A headspace solid phase microextraction arrow method combined with GC/MS was optimized for extraction and analysis of VOC of Microcystis aeruginosa. Ten metabolites with statistical significance were identified by multivariate data analysis. It is suitable to the determination of volatile metabolites in water at the early stage of algae bloom.

Determination of Ultra-Low Level Plutonium Isotopes in Large Volume Environmental Water Samples

GAO Rui-Qin^1,4, HOU Xiao-Lin^1,2,3,*, ZHANG Lu-Yuan^1,2,3, ZHANG Wei-Chao¹, ZHANG Meng-Ting^1,4

¹Xi'an Accelerator Mass Spectrometry Center, State Key Laboratory of Quaternary Geology, Shaanxi Key Laboratory of Accelerator Mass Spectrometry Technology and Application, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, China

²Center for Excellence in Quaternary Science and Global Change, Chinese Academy of Sciences, Xi' an 710061, China

³Open Studio for Oceanic-Continental Climate and Environment Changes, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao 266061, China

⁴University of Chinese Academy of Sciences, Beijing 100049, China

Highlights

建立了一种环境水样中痕量钚同位素的分析方法。采用Ti(OH)₃作为共沉淀剂,对大体积水样中的钚进行预浓缩,通过TEVA树脂萃取色谱分离纯化钚。结果表明,对于20L水样,在钛载体浓度为30mg/L条件下,钚的总回收率为88.9%。萃取色谱分离对铀的去污系数达到1.3×10⁵。用高灵敏度的电感耦合等离子体串联质谱(ICP-MS/MS)同时测定²³⁹Pu和²⁴⁰Pu含量,使用NH₃-He作为反应气体,有效消除了UH⁺离子对²³⁹Pu测量的干扰,通过使用串联四极杆技术,将丰度灵敏度提高5个量级,从而消除了²³⁸U峰拖尾的影响,使分析本底和干扰显著降低,同时,将钚同位素的分析灵敏度提高至990cps/(pg/g)。对20L水样中²³⁹Pu 和²⁴⁰Pu的检出限分别达到1.28×10^-7Bq/L和1.38×10^-7Bq/L。本方法被成功用于分析地表水、水库水和地下水中²³⁹Pu 和²⁴⁰Pu 浓度。

Abstract

Plutonium is an important artificial element, ²³⁹Pu and ²⁴⁰Pu are two major radioisotopes of plutonium in the environment released by human nuclear activities. Due to their high radiotoxicity and bio-toxicity, the determination of these radionuclides is critical in view of radiation protection and environmental radioactivity. It is still a major challenge to accurately determine these radionuclides in environmental water samples due to their extremely low concentrations. In this work, a sensitive analytical method for determination of ²³⁹Pu and ²⁴⁰Pu in environmental water samples was reported. By co-precipitation of plutonium with Ti(OH)₃ followed by separation of plutonium using extraction chromatography with TEVA resin, a recovery of more than 80% for plutonium and decontamination factor of 1.3 × 10⁵ for uranium were achieved. A triple quadrupole inductively coupled plasma mass spectrometry (ICP-MS) with dynamic collision/reaction cell was used for measurement of plutonium isotopes. By using NH₃-He double gasses as collision/reaction gas, ²³⁸U¹H⁺ polyatomic ion interference to measurement of ²³⁹Pu was significantly suppressed and the final abundance sensitivity of ²³⁸U to m/z 239 was reduced to < 1 × 10^–11, and sensitivity of ²³⁹Pu was improved to 990 cps/(pg/g). For 20 L water sample, the detection limits of the method for ²³⁹Pu and ²⁴⁰Pu reached 1.28 × 10^–7Bq/L and 1.38 × 10^‒⁷Bq/L, respectively, which enabled accurate determination of ²³⁹Pu and ²⁴⁰Pu in normal environmental water samples. The developed method was successfully applied to determine ²³⁹Pu and ²⁴⁰Pu in the spiked water and real environmental water samples, and the results indicated that this method was reliable and could be practically applied.

Graphical Abstract

A sensitive method for determination of ultra-low level ²³⁹Pu and ²⁴⁰Pu was established by pre-concentration of plutonium from large volume water using Ti(OH)₃ co-precipitation, purification for plutonium using extraction chromatography with TEVA resin and triple quadrupole ICP-MS measurement of plutonium isotope. NH₃-He was used as reaction gas for elimination of uranium hydride interference and increasing the measurement sensitivity using collision focusing. The method was successfully applied for analysis of environmental water samples from China.

In Situ Carbon Stable Isotope Analysis of Organic Carbon by Laser Ablation-Isotope Ratio Mass Spectrometry

ZHANG Han, WEI Lai, LIAO Xu, WANG Jia-Ni, SHI Qiu-Yue, ZHANG Xian*

Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China

Highlights

自行研制了激光剥蚀取样与稳定同位素质谱联用接口，建立了以激光剥蚀微量取样的微区有机碳同位素分析方法。考察了捕集时间、样品量和激光能量等对同位素分馏的影响，采用3种标样验证了分析方法的准确性。结果表明，此装置可对固体样品进行高灵敏度的连续在线分析,样品用量仅10^-8g，比传统的元素分析同位素质谱联用方法的样品用量降低了104倍。本方法有效避免了激光剥蚀在取样、传输和离子化过程的多种分馏因素,获得了可重复的、高精度的测试结果。以¹³C标记的水稻为例，在叶尖获得了横截面的碳同位素分布差异信息。结合激光剥蚀技术原位取样的优势，此技术可用于考察固体样品微区高分辨的碳同位素分布，在环境、农林学、生态学领域具有良好的应用前景。

Abstract

An interface of laser ablation (LA) and stable isotope ratio mass spectrometry (IRMS) was developed to provide high spatial resolution organic carbon stable isotope analysis. Based on this, a LA-IRMS ¹³C/¹²C analytical method for organic carbon in standards and rice leaf was developed. The results showed that this system could carry out continuous on-line analysis of solid samples with high sensitivity, and the sampling amount was as low as tens of nanograms, which was 10000 times lower than that of traditional element analyzer (EA)-IRMS analysis. This method avoided many fractionation factors effectively in the process of sampling, transmission and ionization, and obtained repeatable and high-precision results. Combined with the advantages of laser ablation technique in situ sampling, the high-resolution carbon isotope distribution information of solid samples was obtained by using this method. This in-situ solid organic carbon isotope measurement technique was stable, reliable with high accuracy, and it would have a broad application prospect in the fields of environment, agriculture, forestry and ecology in the future.

Graphical Abstract

An interface of laser ablation and stable isotope ratio mass spectrometry was developed to provide high spatial resolution organic carbon stable isotope analysis. On the surface of rice leaves (about 1 mm wide), 8 samples were taken successively for ¹³C analysis, and repeat twice.

Detection of Secretion of Exosomes from Individual Cell in Real-Time by Multifunctional Nanoelectrode-Nanopore Nanopipettes

FENG Wen-Nan¹, HE Jin², LI Si-Ying¹, YANG Dan¹, LI Hong-Na¹, YANG Guo-Cheng¹, FU Qiang³, SHAN Yu-Ping^1,*

¹School of Chemistry and Life Sciences, Advanced Institute of Materials Science, Changchun University of Technology, Changchun 130012, China

²Physics Department, Florida International University, Miami 33199, United States

³Jiangxi College of Traditional Chinese Medicine, Fuzhou 344000, China

Highlights

开发了基于玻璃纳米管的细胞外环境外泌体检测方法。制备了多功能纳米探针（MNNPs），在纳米电极表面修饰了抗体以用于外泌体的特异性检测。研究主要集中于多功能纳米探针在保证细胞活性的同时，利用基于纳米孔的电阻脉冲传感技术，对单个人类宫颈癌(HeLa)细胞释放的外泌体进行实时检测。结果表明，MNNPs可以选择性地富集和检测复杂细胞环境中的外泌体，具有应用于各种纳米生物实体研究的潜力。

Abstract

In recent years, exosomes as the intercellular vehicles have received extensive attention for their fundamental roles in biosystem and as novel biomarkers for early detection and therapeutic applications. It has been demonstrated that anti-CD63 can effectively target exosomes from cancer cells. In this work, multifunctional nanoelectrode-nanopore nanopipettes (MNNPs) were prepared to detect exosomes secreted from human cervical cancer cells (HeLa cells) at the single-entity level using the nanopore- based resistive pulse sensing technique. Synthetic liposomes were also measured for comparison. By modifying the anti-CD63 on the carbon nanoelectrode surface near the nanopore, the detected current signals were very different from the signals from the non-modified MNNPs. The differences were induced by the specific interactions between anti-CD63 and the membrane protein CD63 at the surface of exosomes. No obvious differences were observed when liposomes were tested. Furthermore, by utilizing micromanipulation technology, the position of the nanopipette tip could be accurately located, which enabled monitoring the secretion of exosomes from individual cells in a real-time manner. In the control experiment, the probe-to-cell distance was optimized and the HeLa cells incubated with exosomes inhibitor (GW4869) were tested by MNNPs. These significantly reduced translocation signals proved that anti-CD63 modified MNNPs were competent for exosomes detection in complex cellular environments.

Graphical Abstract

A glass nanopipette based extracellular exosome detection method was developed. Multifunctional nanopore-nanoelectrodes nanoprobes (MNNPs) were prepared with the modification of antibody at the nanoelectrode surface for the specific detection of exosomes. The focus of this research is that MNNPs can ensure cell viability and detect exosomes secreted from individual human cervical cancer (HeLa) cells in real time by nanopore-based resistance pulse sensing method. The reported results demonstrate that the MNNPs can selectively enrich and detect exosomes in a complex cellular environment, and have the potential to be applied to the study of various nanosale biological entities.

《分析化学》创刊于1972年，由中国科学院长春应用化学研究所和中国化学会共同主办，报道我国分析化学创新性研究成果，反映国内外分析化学学科的前沿和进展。主要栏目包括特约来稿、研究快报、研究报告、仪器装置与实验技术、评述与进展等。现任名誉主编汪尔康院士，主编杨秀荣院士。《分析化学》期刊于1999年被SCI-E收录，2006年被Scopus、2016年被EI收录。《分析化学》始终致力于打造国际知名学术期刊，以创办中文精品期刊为目标；同时，《分析化学》与国际著名科技出版商Elsevier公司合作，发行本刊的英文电子版

（www.sciencedirect.com/journal/chinese-journal-of-analytical-chemistry，ISSN1872-2040）。

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