RESUMEN
This investigation presents the greener biomimetic fabrication of neodymium selenide nanoparticles (Nd2Se3 NPs) deploying nitrate-dependent reductase as a reducing (or redox) agent, extracted from the fungus, Fusarium oxysporum. The Nd2Se3 NPs, with an average size of 18 ± 1 nm, were fabricated with the assistance of a synthetic peptide comprising an amino acid sequence (Glu-Cys)n-Gly, which functioned as a capping molecule. Further, the NPs were characterized using multiple techniques such as UV-Vis spectroscopy, fluorescence, dynamic light scattering (DLS), and XRD. The hydrodynamic radii of biogenic polydispersed Nd2Se3 NPs were found to be 57 nm with PDI value of 0.440 under DLS. The as-made Nd2Se3NPs were water-dispersible owing to the existence of hydrophilic moieties (-NH2, -COOH, -OH) in the capping peptide. Additionally, these functionalities render the emulsion highly stable (zeta potential -9.47 mV) with no visible sign of agglomeration which bodes well for their excellent future prospects in labeling and bioimaging endeavors.
RESUMEN
Fluorescence and surface-enhanced Raman scattering (SERS) spectroscopy were employed to investigate the cellular uptake of rhodamine 6G (R6G) alone and of R6G loaded with gold nanoparticles (AuNPs) by endothelial cells. R6G plays the role of a Raman reporter in SERS but also displays strong fluorescence. The presence of bare R6G molecules and R6G-AuNPs in the cytoplasm of the cells is detected via the 2D fluorescence of the dye after a 0.5 h of the incubation with R6G and R6G-AuNPs, and then the concentration of the dye increases within 4 h of exposure. The examination of the cellular uptake of the R6G and R6G-AuNPs species at different temperatures suggests that the internalization of the R6G-AuNPs into endothelial cells occurs mainly via endocytosis. 3D fluorescence imaging of R6G inside cells reveals inhomogeneous distribution of the dye in the cytoplasm. The SERS signal of the Raman reporter inside the cell disappears after 2 h of incubation with R6G-AuNPs and then amino acid residues, purines and pyrimidines become SERS-active via their interactions with the gold. The results highlight the significance of using multiple techniques to cover a spectrum of issues in the application of SERS nanosensors for probing an intracellular environment under comparable and standardized conditions. FigureCellular uptake of bare rhodamine 6G and rhodamine 6G adsorbed onto AuNPs were studied on endothelial cells using fluorescence and surface-enhanced Raman spectroscopy. The internalization of R6G-AuNPs occurs via endocytosis and diffusion resulting in uneven distribution in the cytoplasm.
RESUMEN
The effect of incorporating carbon nanotubes (CNTs) in the gel matrix on the electrophoretic mobility of proteins based on their molecular weight differences was investigated using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). More specifically, a reduction in standard deviation in the molecular weight calibration plots by 55% in the case of multiwalled carbon nanotubes (MWCNTs) and by 34% in the case of single-walled carbon nanotubes (SWCNTs) compared with that of pristine polyacrylamide gels was achieved after incorporating an insignificant amount of functionalized CNTs into the gel matrix. A mechanism based on a more uniform pore size distribution in CNT modified polyacrylamide gel matrix is proposed. Furthermore, the impact of SWCNTs and MWCNTs on the mobility of proteins in different molecular weight regimes at a given acrylamide concentration offers a tunable gel matrix in terms of the selection of molecular weight ranges of proteins. The robustness and excellent reproducibility of the CNT-PAGE protocol are expected to have a significant impact on the molecular weight determination of newly isolated proteins.
