WATER RESEARCH
·
2021
·
IF 11.236
Huiwen Cai,Mengdi Chen,Fangni Du,Sara Matthews,Huahong Shi
Nanoplastics are an emerging contaminant in aquatic environments. However, analytical methods for the separation, concentration, and identification of nanoplastics, which are essential to assess nanoplastic presence in the environment, are lacking. Here, we developed a new and easy-to-use method to separate and enrich nanoplastics in field water samples with ultracentrifugation. River water was spiked with polystyrene fragments (< 1000 nm) at an environmentally relevant concentration (10 8 –10 9 particles/L). The polystyrene fragments were successfully separated and enriched by a factor of nearly 50 times with a high recovery rate (87.1%) after undergoing our process. Particles were then characterized using UV-vis spectroscopy, scanning electron microscopy (SEM), and enhanced darkfield microscopy with a hyperspectral imaging (HSI) spectrometer. These techniques are non-destructive and allow the assessment of plastic concentration, morphology, and polymer type. Our method can potentially be applied to other water samples to supply clean, enriched nanoplastic samples that can facilitate their identification in environmental samples.
研究领域:
环境科学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2025
·
IF 8.5
Xinyu Qian,Yuqian Guo,Yumeng Zhao,Leilei Hou,Yun Cheng,Linghua Chen,Shuo Yang,Hongjie Zhang
The swelling performance of the biological macromolecules of cellulose in aqueous N -methyl-morpholine-N-oxide (NMMO) solution is a critical factor in improving cellulose dissolution efficiency during lyocell process. We focused on the diffusion behavior of NMMO solvent during cellulose swelling and dissolution process using a novel centrifugation method, clarifying the relationship between NMMO retention value, fiber structural properties, and dissolution efficiency. An effective quantitative index for evaluating the swelling performances of cellulose is NMMO-retention, which was defined by investigating the removal of aqueous NMMO solution from swollen cellulose fibers using centrifugal method. Based on the variation of NMMO-retention and centrifugal force at 500 and 3000 g , the removal process was divided into three stages: rapid removal stage (0–500 g), slow removal stage (500–3000 g), and residual removal stage (3000–5000 g). In addition, the relationship between fiber structural properties (fiber length, width, fine content, and specific surface area) and swelling-dissolution performance was established. The results indicate that the NMMO-retention of cellulose is a comprehensive reflection of the fiber structural characteristics, and it shows an obvious negative correlation with the dissolution time of cellulose. The cellulose that shows the highest NMMO-retention (729.5 %) after swelling has the shortest dissolution time (20 min) during subsequent dissolution.
研究领域:
材料科学
·
生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FOOD RESEARCH INTERNATIONAL
·
2024
·
IF 7
Shijie Liu,Lijun Zhao,Miaoyun Li,Jong-Hoon Lee,Yaodi Zhu,Yanxia Liu,Lingxia Sun,Yangyang Ma,Qiancheng Tu,Gaiming Zhao,Dong Liang
There is an urgent need for quick, sensitive, thorough, and low-cost preliminary screening and rapid identification method for probiotic resource development. Here, we constructed a culture-free, accurate and sensitive “separation-enrichment-detection” rapid evaluation and identification method of probiotics in fermented food based on Ramanomes technology, and established a Ramanome reference of lactic acid bacteria and yeasts by AgNPs nanostructure array (AgNPs NSA) chips with uniform “hot spots” and high signal enhancement ability as SERS substrates. Systematic cluster analysis could clearly distinguish among different genera of lactic acid bacteria and yeast, and could indicate the affinity and difference between lactic acid bacteria of the same genus and yeast of the same genus. The recognition accuracy of convolutive neural networks was 100 %, and the recognition sensitivity was less than 10 CFU/mL. We constructed a probiotic isolation and enrichment method by velocity gradient centrifugation and density gradient differential centrifugation, and the average recoveries of lactobacilli and yeasts were greater than 98 % in the practical application, and the accuracy of the verified classification was 100 %. In conclusion, this study has established a preliminary screening strategy of “screening before cultivating” for lactic acid bacteria and yeasts, which breaks through the principle limitation of the current traditional paradigm of “cultivating before screening”. It can greatly improve the preliminary screening rate of probiotics in fermented foods, and provide a good technical support for the mining of probiotic resources from environmental or complex matrix samples.
研究领域:
食品科学
·
微生物学
·
生物技术
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Biosensors-Basel
·
2025
·Vol. 15
·期 5
·298
·
IF 5.6
Tianyu Zhou,Zhiyang Zhang
Colloidal noble metal nanoparticle aggregates have demonstrated significant advantages in surface-enhanced Raman scattering (SERS) analysis, particularly for online detection, due to their excellent optical properties, spatial homogeneity, and fluidic compatibility. However, conventional chemically induced aggregation methods (such as salt-induced nanoparticle aggregation) suffer from uncontrolled aggregation, limited stability, and narrow detection windows, which restrict their quantitative and long-term applications. In this study, we developed a non-chemical method for fabricating stable colloidal aggregates from uniform β-cyclodextrin-stabilized silver nanoparticles (β-CD@AgNPs) via centrifugation. By precisely controlling the addition rate of silver nitrate, we synthesized β-cyclodextrin-stabilized silver nanoparticles with a uniform size. Surprisingly, these nanoparticles can form highly dispersed and homogeneous colloidal aggregates simply via centrifugation, which is completely different from the behavior of traditional ligand-modified nanoparticles. Notably, the resulting aggregates exhibit excellent SERS enhancement, enabling the sensitive detection of various dyes at nanomolar levels. Furthermore, they maintain a stable SERS signal (RSD = 6.99%) over a detection window exceeding 1 h, markedly improving signal stability and reproducibility compared with salt-induced aggregates. Additionally, using pyocyanin as a model analyte, we evaluated the quantitative performance of these aggregates (LOD = 0.2 nM), achieving satisfactory recovery (82–117%) in spiked samples of drinking water, lake water, and tap water. This study provides a facile strategy for fabricating stable colloidal SERS substrates and paves the way for the advancement of SERS applications in analytical sciences.
研究领域:
分析化学
·
纳米技术
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ANALYTICAL CHEMISTRY
·
2022
·
IF 8.008
Siyuan Jing,Yu Huang,Yinjuan Chen,Xueqing He,Zhong Chen,Xingyu Lu,Minghuo Wu,Thomas C. Wanger
Nano-/microplastics (NMPs, particle diameter < 5 mm) are widespread emerging pollutants causing diverse impacts on organisms due to their sizes, shapes, and chemical properties. Despite the fast increase in NMP research, an effective method to separate and identify NMP types from environmental samples is still lacking. Here, we developed a simple and effective approach for the non-destructive extraction and separation of various types of NMPs from environmental samples by density gradient ultracentrifugation (DGU). For the first time, DGU was capable to separate various NMPs from the complex matrix with high selectivity (100%), purity (93%), and applicability. Through a gradually changing density of the density gradient medium by changing the concentrations or volumes of CsCl/water solution (from 0.00065 to 0.01989 g cm–3 mm–1), various NMPs (with particle sizes as little as 50 nm) could be extracted and separated from soil samples with high recovery (78.5–96.0%). We confirmed the effectiveness and compatibility of DGU through a correct identification of all types of NMPs separated from artificial soil samples with Raman spectroscopy, simultaneous thermal analysis (STA), and pyrolysis–gas chromatography–mass spectrometry (Py–GC–MS). DGU is compatible with all analytical processes compared to other existing methods with much less sample pretreatment time (0.5 h). Overall, DGU is an effective and cheap method (2.2 USD/sample) to separate NMPs from environmental samples such as soil and water and, hence, can facilitate research on NMPs related to terrestrial and marine environments as well as human health.
研究领域:
环境科学
·
分析化学
✓ 已验证
DOI
高影响因子
ANALYTICAL CHEMISTRY
·
2025
·
IF 6.7
Bangming Wang,Yan Zhao,Mingzhu Zhao,Yuke Han,Hui Zhang,Weiheng Kong,Fengli Qu
Systematic analysis of the information content of biological external vesicles (BEVs) is essential for understanding the complex relationships between metabolic processes and cells at a systemic level. Although considerable efforts have been made to enrich BEVs, their comprehensive analysis in a way that maintains and stabilizes information maintenance at high doses remains a challenge. To address this issue, we developed a metal–organic nanoslice-coupled exocytosis phospholipid layer method that utilized subtle interactions between the metal–organic nanoslice and the phospholipid molecular layer of the membrane to achieve the convenient and efficient enrichment of BEVs. The method bypassed the conventional ultracentrifugation and size exclusion separation and helped to highly preserve the internal information on BEVs. By integrating and analyzing the enriched BEVs for elements such as membrane proteins and endotoxins, the simplicity and robustness of the metal–organic nanoslice-coupled vesicle surface phospholipid layer technology were verified, which provided a reliable platform for studying the cellular events associated with outer vesicles and expanded the biological applications of the metal–organic nanoslice.
研究领域:
生物化学
·
分子生物学
·
纳米医学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2021
·Vol. 11
·期 45
·28410-28419
·
IF 3.361
Shu Zhou
We report the rapid separation and purification of lead halide perovskite quantum dots (QDs) in a nonpolar solvent by using a convenient and efficient differential separation method. Size-selective precipitation effectively separates the perovskite QDs from larger aggregates and provides direct evidence for strong quantum confinement in the photoluminescence (PL). Significantly, the size-selected perovskite QDs are readily well-dispersed in a nonpolar solvent and remain stable in ambient air (humidity > 60%) for >20 days. These enable measurement of the electronic band structure of versatile perovskite QDs as a function of size for the first time. Despite a clear blue-shift of the optical bandgap, the lowest unoccupied molecular orbital (LUMO) readily moves towards the vacuum level while the highest occupied molecular orbital (HOMO) changes slightly, in good agreement with that observed in the quantum size effect tuning of quasi-2D perovskites and colloidal semiconductor QDs. The results demonstrate the possibility of utilizing differential centrifugation as a novel method to attain size-dependent tunability for property-specific perovskite-QD based optoelectronic applications.
研究领域:
材料科学
·
光电子学
✓ 已验证
DOI
PubMed
高影响因子
FOOD HYDROCOLLOIDS
·
2020
·
IF 7.053
Kang Ni,Yating Gao,Xiaodong Ye
The structure and formation mechanism of 15S globulin of soybeans were investigated. After purification, 15S-rich fraction (75.6%) and 11S-rich fraction (94.3%) were obtained and further characterized with analytical ultracentrifugation (AUC) and transmission electron microscope (TEM). The results show that the molar masses of 11S and 15S are 313 kDa and 651 kDa, respectively, and the weight percentages of the monomer , dimer, and trimer in the TEM images are consistent with those of 11S, 15S, and 21S fractions measured by AUC, indicating that 15S and 21S are dimers and trimers of 11S monomer, respectively. The size of the 15S molecules is 21.1 nm × 10.4 nm, suggesting that two 11S molecules interact with each other from the side position. Moreover, the contents of subunits were determined by a combination of AUC and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) with the addition of 20 mM sodium dodecyl sulfate (SDS) and 10 mM 2-mercaptoethanol (2-ME). The content of the species with a sedimentation coefficient of 4.3 S in 15S-rich fraction, which is assigned as AB-SS-AB subunits, is significantly higher than that in 11S-rich fraction with the addition of SDS; this species disappears with the addition of 2-ME, demonstrating that AB-SS-AB subunits are formed by disulfide groups from two AB subunits. These disulfide groups may locate in a non-polar interior, which is not accessible to 2-ME when the protein remains its native structure.
研究领域:
植物生物化学
·
蛋白质结构与功能
✓ 已验证
DOI
高影响因子
ANALYTICA CHIMICA ACTA
·
2024
·
IF 5.7
Siyuan Jing,Yanting Wang,Jiaying Zheng,Xin Li,Yinjuan Chen,Minghuo Wu,Weiping Liu,Thomas C. Wanger
Particle size is an important indicator to evaluate the environmental risk and biotoxicity of nanoplastic (NP, particle diameter <1000 nm). The methods available to determine size classes of NP in environmental samples are few and are rare to achieve efficient separation and recycling of NP with close particle sizes. Here, we show that rate-zonal centrifugation (RZC) can quickly and efficiently collect NP of different sizes based on their sedimentation coefficients. When combined with cloud-point extraction (CPE) and pyrolysis−gas chromatography−mass spectrometry (Py-GC-MS), our method can quantify three NP particle-size classes separately (including 100 nm, 300 nm, and 600 nm) in aqueous samples with high recovery (81.4 %–89.4 %), limits of detections (LODs, 33.5–53.4 μg/L), and limits of quantifications (LOQs, 110.6–167.2 μg/L). Compared with the conventional sample pretreatment process, our method can effectively extract and determine the NP with different sizes. Our approach is highly scalable and can be effectively applied to NP in a wide range of aquatic environments . Meanwhile, our approach is highly scalable to incorporate diverse assays to study the environmental behaviours and ecological risks of NP.
研究领域:
环境科学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Advanced Optical Materials
·
2023
·Vol. 11
·期 16
·2300306
·
IF 9
Wei Shen,Zhan Su,Shuo Chen,Yujun Dai,Yue Qiu,Yanfeng Chen,Jiayu Jiang,Jianbin Zhang,Yun Wang,Hao Cui,Yanxing He,Kun Cao,Bo Cai,Lihui Liu,Shufen Chen
Development of high-performance and stable pure red perovskite light-emitting devices (LEDs) promotes commercialization of perovskite. Benefiting from the quantum confinement effect, pure red CsPbI 3 quantum dots (QDs) can avoid the color drift issue for mixed halide systems. Herein, a facile temperature-dependent hot-injection method combined with low temperature gradient centrifugation is employed to prepare 5.60 ± 0.05 nm pure red QDs. The QDs exhibit 642 nm photoluminescence (PL) with 37 nm full width at half maximum, and their Commission Internationale de l'Eclairage (CIE) coordinates located at (0.708, 0.292) match well with standard pure red for Rec. 2020. The PL half-lifetime for pure red QDs solution is 210 days under ambient conditions, and both the X and Y coordinates of CIE only fluctuate within (0.002, 0.002). Finally, a simple NH 4 I post-treatment to decrease ligand length further boosts the QDs conductivity, and the pure red LED exhibits 9.4% maximum external quantum efficiency. The electroluminescence spectra exhibits a sharp peak at 645 nm, and their CIE coordinates are located at (0.707, 0.290). Furthermore, the pure red LED exhibits both good working and color stability. Its half-lifetime is 25.1 min and color drifts are only (0.002, 0.002) after 30.0 min of continuous working at 60 cd m −2 with a constant current density of 3.5 mA cm −2 .
研究领域:
材料科学
·
光电技术
·
纳米科技
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POLYMER SCIENCE
·
2020
·Vol. 58
·期 5
·756-765
·
IF 0
Miao Zhang,Nairong Hao,Yating Gao,Lianwei Li,Xiaodong Ye
Separation and characterization on mixed solutions of hyperbranched and linear polystyrenes was achieved using size-exclusion chromatography (SEC) as the first dimension and analytical ultracentrifugation (AUC) as the second dimension. The results show that linear and hyperbranched polystyrenes with similar hydrodynamic sizes (one fraction from SEC) can be separated by AUC according to the molar mass, and the separation efficiency decreases with the increasing of the retention volume in SEC. Moreover, the molar masses determined by AUC are consistent with the values measured by SEC-refractive index (RI) and SEC-multi-angle light scattering (MALS) detection. Furthermore, the result shows that the separation efficiency decreases with the increasing of the subchain length of hyperbranched polystyrenes. Our study lays a solid foundation for future studies to separate polymers with different topologies by a combination of SEC and AUC. Graphical Separation and characterization of mixed solutions of hyperbranched and linear polystyrenes has been achieved using size-exclusion chromatography (SEC) as the first dimension and analytical ultracentrifugation (AUC) as the second dimension. The results show that linear and hyperbranched polystyrenes with similar hydrodynamic sizes (one fraction from SEC) can be separated by AUC according to the molar mass, and the separation efficiency decreases with the increasing of the retention volume in SEC.
研究领域:
高分子化学
·
分析化学
✓ 已验证
DOI
LANGMUIR
·
2020
·
IF 3.557
Mengdi Chen,Shaoyan Wang,Bingwen Hu
Significant progress has been made in the synthesis and application of core–shell nanoparticles in the past decade. But particle agglomerations are hard to avoid as the formation mechanisms of core–shell nanoparticles are still vague and not clear even for the simplest and most straightforward hard-templating method. Here, analytical ultracentrifugation (AUC) is applied to investigate the formation of polystyrene@ZIF-8 core–shell nanoparticles, as a model to understand the hard-templating method. It has been found that the concentration of the ZIF-8 precursor influences both the ZIF-8 shell formation and the agglomeration of the polystyrene (PS) template. An overdiluted ZIF-8 precursor is not suitable for ZIF-8 shell formation, while a highly concentrated ZIF-8 precursor causes strong aggregation of the PS core. By applying the optimal precursor concentration identified by AUC, well-dispersed polystyrene@ZIF-8 core–shell nanoparticles can be obtained.
研究领域:
材料科学
·
化学工程
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）