Conformation of Polyethylene Glycol inside Confined Space: Simulation and Experimental Approaches

Abstract

The modification of the inner nanopore wall by polymers is currently used to change the specific properties of the nanosystem. Among them, the polyethylene glycol (PEG) is the most used to prevent the fouling and ensure the wettability. However, its properties depend mainly on the chain structure that is very difficult to estimate inside this confined space. Combining experimental and simulation approaches, we provide an insight to the consequence of the PEG presence inside the nanopore on the nanopore properties. We show, in particular, that the cation type in the electrolyte, together with the type of electrolyte (water or urea), is at the origin of the ion transport modification in the nanopore.

Detection of Amyloid-β Fibrils Using Track-Etched Nanopores: Effect of Geometry and Crowding

“…The other one (note pore 3, d = 28 ± 2 nm and D = 635 ± 115 nm with a thickness of 13 μm) was functionalized with PEG 20 kDa (Table SI-1 in Supporting Information). The success of the nanopore functionalization is directly characterized by a decrease of the current rectification and the nanopore conductance due to the grafting on carboxylateending moieties by uncharged PEG chains at the surface, as previously demonstrated 30 (Figure SI-1).…”

“…Our conical nanopore has been described in previous papers. , Its dimensions ( R tip = 3 nm, R base = 3.5 nm, and length = 14.8 nm) were obtained through the association of several carbon nanotube sections of different radii. The chemical structure of the PET nanopore as used in the experiments was modeled by replacing one-third of the carbon atoms constituting the nanopore with oxygen atoms.…”

“…First, the intrinsic method of fabrication allows the nanopore being already filled with an aqueous solution after chemical etching, thus limiting the problem of the wettability. In addition, surface modification is easy to achieve in aqueous solution and it is possible to know the surface density of the grafting . Finally, the track-etched nanopores are exceptionally stable after PEG grafting and can be used for resistive pulse experiments for several weeks. , This was also the case for the SiN functionalized with PEG incorporated in a microfluidic chamber …”

“…In addition, surface modification is easy to achieve in aqueous solution and it is possible to know the surface density of the grafting. 30 Finally, the track-etched nanopores are exceptionally stable after PEG grafting and can be used for resistive pulse experiments for several weeks. 28,31 This was also the case for the SiN functionalized with PEG incorporated in a microfluidic chamber.…”

Cooperative electrolyte-PEG interactions drive the signal amplification in a solid-state nanopore

“…Salt gradients can also be used to improve the translocation frequency across a nanopore, but it does not affect the speed nor the current magnitude of the single molecule events (27). Alternatively, the nanopore surface can be chemically modified to slow down the translocation of analytes (28)(29)(30)(31)(32) but this method is difficult to generalize as it needs to be tailored for each analyte.…”