AFM imaging of functionalized carbon nanotubes on biological membranes

Abstract

Multifunctional carbon nanotubes are promising for biomedical applications as their nano-size, together with their physical stability, gives access into the cell and various cellular compartments including the nucleus. However, the direct and label-free detection of carbon nanotube uptake into cells is a challenging task. The atomic force microscope (AFM) is capable of resolving details of cellular surfaces at the nanometer scale and thus allows following of the docking of carbon nanotubes to biological membranes. Here we present topographical AFM images of non-covalently functionalized single walled (SWNT) and double walled carbon nanotubes (DWNT) immobilized on different biological membranes, such as plasma membranes and nuclear envelopes, as well as on a monolayer of avidin molecules. We were able to visualize DWNT on the nuclear membrane while at the same time resolving individual nuclear pore complexes. Furthermore, we succeeded in localizing individual SWNT at the border of incubated cells and in identifying bundles of DWNT on cell surfaces by AFM imaging.

Spontaneous insertion of carbon nanotube bundles inside biomembranes: A hybrid particle-field coarse-grained molecular dynamics study

“…Their large surface area allows attachment (of chemical or physical nature) of drug molecules [5][6][7] and the empty core of the CNTs provides an opportunity to exploit them as nano-containers for drug [8,9] or any desired biologically active molecule encapsulation [10,11]. For this reason, several experimental studies have been performed in order to understand the pathways of internalization [12][13][14][15][16][17][18][19]. Al-Jamal et al [12] have studied the cellular mechanism of functionalized Multi Walled CNTs (MWCNTs) by 3D electron tomography imaging.…”

Carbon nanotubes: Impacts and behaviour in the terrestrial ecosystem - A review

“…The ratio (intensity or area) between the D and G bands allows measuring the proportion of defectuous carbon present in the sample [50]. There are several other techniques to characterize and detect CNTs such as atomic force microscopy (AFM) [51], dynamic diffusion of light, although this may not be well-suited for elongated and flexible nanomaterials such as CNTs [52], infrared spectroscopy [53] or photoluminescence [54]. Lutsyk et al [55] recently proposed a new method using selective photoluminescent probes based on ionic complexes with organic dyes.…”

Detection of erythrocytes in patients with Waldenström macroglobulinemia using atomic force microscopy

“…An Autoprobe CP AFM (Veeco, Plainview, USA) in contact mode, widely used to measure the topography of cells [12,16,17], was applied to detect the immobilized erythrocytes at room temperature. Gold-coated silicon nitride tips (UL20B; Park Scientific Instruments, Baldwin Park, USA) with a spring constant of 2.5 N/m and a tip diameter of 20 nm were used for the AFM experiments.…”