We describe a rapid, simple, and highly efficient capillary electrophoresis (CE)-based method for the analysis of nanoparticles (NPs). In this study, we used the reversed electrode polarity stacking mode (REPSM) of CE to assess the feasibility of enhancing the detection of Au NPs and Au/Ag NPs, optimizing parameters such as the length of time for which the REPSM was applied, the concentrations of the buffer and the sodium dodecylsulfate (SDS) surfactant, and the pH. Under the optimized on-line enhancement conditions [buffer: SDS (40 mM) and 3-cyclohexylamino-1-propanesulfonic acid (CAPS; 10 mM) at pH 10.0; applied voltage: 20 kV; REPSM applied for 24s], the detection limits of the Au NPs and Au/Ag NPs increased by ca. 30- and 140-fold, respectively. In addition, when the NPs were subjected to on-line enhancement and separation by CE using diode array detection (DAD), this approach allowed chemical characterization of the NP species. Our results suggest that such CE analyses will be useful for accelerating the rates of fabrication and characterization of future nanomaterials.
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http://dx.doi.org/10.1016/j.chroma.2007.05.072 | DOI Listing |
Int J Biol Macromol
December 2024
Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences (CAAS), Key Laboratory of Agro-Products Processing, Ministry of Agriculture and Rural Affairs, Beijing, China. Electronic address:
Saccharides are the dominant factor shaping the texture of freeze-dried products. This study investigated the impact of various molecular-weight saccharides at different concentrations on the physical properties and intermolecular interactions of pectin-CMC cryogels by experiment and molecular dynamic (MD) simulations. Results showed that the increased shrinkage of cryogels and enhanced molecular interactions between saccharides and pectin-CMC were mechanisms that enhanced the hardness of cryogels.
View Article and Find Full Text PDFJ Chromatogr A
December 2024
KU Leuven - University of Leuven, Pharmaceutical Analysis, Department of Pharmaceutical and Pharmacological Sciences, O&N2, PB 923, Herestraat 49 3000 Leuven, Belgium. Electronic address:
Natural products (NPs) play an important role in drug discovery and drug development due to their diverse chemical properties and biological activities. In the present work, an on-line capillary electrophoresis (CE) method was developed and applied to screen protein tyrosine phosphatase 1B (PTP1B) inhibitors in NPs. As a generic technique, transverse diffusion of laminar flow profiles (TDLFP) was utilized to mix all reactants in the capillary for on-line enzymatic reaction.
View Article and Find Full Text PDFPhys Chem Chem Phys
January 2025
Institute for Physical Chemistry, University of Münster, Münster, Germany.
As the demand for high-energy batteries to power electric vehicles continues to grow, Ni-rich cathode materials have emerged as promising candidates due to their high capacity. However, these materials are prone to rapid degradation under increased voltages, posing significant challenges for their long-term stability and safety. In this study, we investigate the effects of tantalum (Ta) doping on the performance and stability of LiNiMnCoO (NMC811) cathode materials.
View Article and Find Full Text PDFEng Life Sci
December 2024
Chemical Development Novo Nordisk A/S Bagsværd Denmark.
Raman spectroscopy, a robust and non-invasive analytical method, has demonstrated significant potential for monitoring biopharmaceutical production processes. Its ability to provide detailed information about molecular vibrations makes it ideal for the detection and quantification of therapeutic proteins and critical control parameters in complex biopharmaceutical mixtures. However, its application in fermentations has been hindered by the inherent strong fluorescence background from the cells.
View Article and Find Full Text PDFiScience
December 2024
The Institute of Mechanical and Electrical Engineering, China Jiliang University, Hangzhou 310018, China.
Addressing the joint control problem of pneumatic muscle-driven robots, this study aims to design a bionic reflex mechanism to enhance the robots' adaptive capacity to various disturbances. Based on the biological reflex mechanism, we developed a spindle reflex and deep tendon reflex control system based on CPG (central pattern generator) to mitigate the sudden impact on the hip joint and the continuous blocking force on the knee joint, respectively. The spindle reflex controller incorporates the fast response of sliding mode control to effectively minimize the trajectory deviation of the hip joint under impact disturbances.
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