Year: 2018
Type: article
Abstract: Many nanomaterials are promising biosensor elements due to capabilities for transduction of biomolecular interactions into an electrical or optical signal. Certain nanomaterials have intrinsic charges and are thus susceptible to electrostatic forces that may enhance or attenuate their response. Here, using a combination of experimental and computational approaches, we found and characterized a critical role of the solvent salt conditions in determining the extent of optical changes due to anionic analyte interaction with an intrinsically responsive nanomaterial, single-walled carbon nanotubes. Using a well-characterized model anionic analyte, we found that monovalent salts enabled greater optical changes of a polyanion-bound carbon nanotube in a highly dose-dependent manner but not with a neutrally charged analyte. Molecular dynamics simulations were used to derive a quantitative understanding of this mechanism from a free-energy perspective. We also show that salt can be used to enhance the sensitivity of detection for a polyanionic analyte. These results suggest that electrostatic screening is an important parameter for intrinsically charged nanoparticle sensors and it may be tuned to control the response to analytes.
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
Funders: National Science Foundation, U.S. Department of Energy, Ira Sohn Research Conference Foundation, Honorable Tina Brozman Foundation, Memorial Sloan-Kettering Cancer Center, Pershing Square Foundation, Pershing Square Sohn Cancer Research Alliance, National Institutes of Health, NIH Office of the Director, National Cancer Institute, Division of Chemical, Bioengineering, Environmental, and Transport Systems
OpenAlex ID: W2800671131