Issue 8, 2020

Hydrogen bonding rather than cation bridging promotes graphene oxide attachment to lipid membranes in the presence of heavy metals

Abstract

Interactions between graphene oxide (GO) and cell membranes play a crucial role in the nanotoxicity of GO toward organisms. However, little is known about interactions of GO with lipid membranes in the presence of heavy metals. This study investigated the attachment of GO and adsorption of heavy metals onto simulated cell membranes (spherical supported lipid bilayers, SSLBs) formed by cationic, neutral and anionic lipids, i.e., SSLB(+), SSLB(0) and SSLB(−), using batch experiments, density functional theory (DFT) calculations, and spectroscopic analyses. In the binary systems, the SSLBs bind with GO through hydrogen binding and with heavy metals via complexation. The attachment of GO or adsorption of heavy metals onto SSLBs decreased in the order SSLB(−) > SSLB(0) > SSLB(+), largely controlled by the type and number of functional groups in the SSLBs. Evidence from batch experiments, DFT calculations and spectroscopic analyses confirmed that in the ternary system GO first binds with metals, and then the GO–metal complexes attach to SSLBs via hydrogen bonding through GO rather than cation bridging through metals. Moreover, metal adsorption onto GO strengthens hydrogen bonding by withdrawing electrons from the GO surface. Therefore, in the ternary system, heavy metals promoted the GO attachment to SSLBs. However, GO suppressed the adsorption of heavy metals onto SSLBs by blocking the adsorption sites via steric hindrance. This study highlighted the importance of molecular interactions on assessing the nanotoxicity of GO to cells in the coexistence of heavy metals.

Graphical abstract: Hydrogen bonding rather than cation bridging promotes graphene oxide attachment to lipid membranes in the presence of heavy metals

Supplementary files

Article information

Article type
Paper
Submitted
09 abr. 2020
Accepted
05 jun. 2020
First published
12 jun. 2020

Environ. Sci.: Nano, 2020,7, 2240-2251

Hydrogen bonding rather than cation bridging promotes graphene oxide attachment to lipid membranes in the presence of heavy metals

H. Li, H. Ji, R. Zhang, W. Zhang, B. Pan, W. Liu and W. Sun, Environ. Sci.: Nano, 2020, 7, 2240 DOI: 10.1039/D0EN00366B

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements