Near-Infrared Fluorescence Microscopy of Single-Walled Carbon Nanotubes in Phagocytic Cells

Abstract

The uptake of pristine single-walled carbon nanotubes into macrophage-like cells has been studied using the nanotubes' intrinsic near-infrared fluorescence. Macrophage samples that have been incubated in growth media containing suspended single-walled nanotubes show characteristic nanotube fluorescence spectra. The fluorescence intensities increase smoothly with incubation time and external nanotube concentration. Near-infrared fluorescence microscopy at wavelengths above 1100 nm provides high contrast images indicating localization of nanotubes in numerous intracellular vesicles. Nanotube uptake appears to occur through phagocytosis. Population growth of macrophage cultures is unaffected by exposure to single-walled nanotube concentrations of ca. 4 mug/mL for up to 96 h.

Analysis of engineered nanomaterials in complex matrices (environment and biota): General considerations and conceptual case studies

“…Hyperspectral reflectance imaging such as CytoViva may be useful for tracking CNMs in tissues; however, the typically high absorbance of CNMs across the visible spectrum may limit sensitivity. For SWNTs, a highly sensitive and selective imaging microscopy technique is available based on NIRF microscopy [31]. This technique can detect single semiconductive SWNT particles in biological samples and has been used to examine the biodistribution of these CNMs in Drosophila melanogaster [32].…”

“…Chem. 31,2012fresh water sediments. An individual porewater subsample would be beneficial to determine the pore water dispersed fraction [67].…”

“…3). If the stoichiometry for each individual particle is 31,2012known together with the density of the material and the iontransfer-efficiency, the particle size can be calculated in principle. Although the height/area of the signal is a measure of the particle size, the number of flashes per sample volume transferred into the plasma relates to the number concentration of the respective particle in the sample if the transfer efficiency sample into the ICP in terms of number of particles is known.…”

“…Chem. 31,2012requiring engineered AgNP enrichment in the sample. Linear combination analysis is critically dependent on the proper selection of model compounds, proper sample preparation, and more than one plausible solution that fits the observed data can be possible [95].…”

Carbon Nanotubes for Electronic and Electrochemical Detection of Biomolecules

“…[19] With diameters similar to or smaller than those of individual proteins, CNTs are expected to serve as high-performance electrical conduits for interfacing with biological systems. [20] Thus, there is enormous interest in utilizing CNTs for biosensor applications, where sensing motifs can be coupled to their optical [21,22] and electronic properties. [23] The incorporation of carbon nanotubes has the potential to address a variety of long-standing issues with respect to biosensing.…”