Bacterial Adhesion to Graphene Oxide (GO)-Functionalized Interfaces Is Determined by Hydrophobicity and GO Sheet Spatial Orientation

Jinkai Xue, Sara BinAhmed, Zhaoxing Wang, Nathan G. Karp, Benjamin L. Stottrup, Santiago Romero Vargas Castrillon

Research output: Contribution to journalArticlepeer-review

16 Scopus citations

Abstract

The potential of graphene oxide (GO) in environmental applications, such as the development of antimicrobial materials and low-fouling membranes, has thus far been hindered by an incomplete understanding of bioadhesion mechanisms on GO interfaces. Using atomic force microscopy (AFM)-based single-cell force spectroscopy, we investigate the adhesion of single Pseudomonas fluorescens cells on GO-functionalized interfaces possessing distinct morphologies. Specifically, we investigate Si-GO surfaces, in which Langmuir-Blodgett GO films are transferred to Si wafers by dip-coating, forming an immobilized layer of horizontally arranged GO nanosheets, and PLL-GO surfaces, where GO nanosheets, edge-tethered to poly-l-lysine, form an interface characterized by morphological and conformational disorder. We observe strong adhesion forces on both Si-GO and PLL-GO surfaces; analysis of the pull-off forces in terms of the worm-like chain model reveals that adhesion is driven by hydrophobic interactions between proteinaceous adhesins on P. fluorescens and graphenic basal planes. We further show that adhesion forces are significantly stronger on Si-GO surfaces that facilitate interactions with graphenic planes, compared to PLL-GO surfaces, which show weaker adhesion due to steric and electrostatic repulsion. These results therefore demonstrate that the spatial orientation and conformational disorder of GO nanosheets are key factors governing the interfacial properties of graphene nanomaterials.

Original languageEnglish (US)
Pages (from-to)14-19
Number of pages6
JournalEnvironmental Science and Technology Letters
Volume5
Issue number1
DOIs
StatePublished - Jan 9 2018

Bibliographical note

Funding Information:
This work was supported by grants to S.R.-V.C. from the United States Geological Survey (MN WRC 2015MN362B), 3M Co. (Non-Tenured Faculty Award), and the Environment and Natural Resources Trust Fund, as recommended by the Legislative-Citizen Commission on Minnesota Resources. Portions of this work were carried out in the Characterization Facility and Minnesota Nano Center, University of Minnesota, which receive partial support from NSF through the MRSEC and NNIN programs, respectively. Work at Augsburg University was supported by NSF MRI 1040126.

Funding Information:
This work was supported by grants to S.R.-V.C. from the United States Geological Survey (MN WRC 2015MN362B), 3M Co. (Non-Tenured Faculty Award), and the Environment and Natural Resources Trust Fund as recommended by the Legislative-Citizen Commission on Minnesota Resources. Portions of this work were carried out in the Characterization Facility and Minnesota Nano Center, University of Minnesota, which receive partial support from NSF through the MRSEC and NNIN programs respectively. Work at Augsburg University was supported by NSF MRI 1040126.

Fingerprint

Dive into the research topics of 'Bacterial Adhesion to Graphene Oxide (GO)-Functionalized Interfaces Is Determined by Hydrophobicity and GO Sheet Spatial Orientation'. Together they form a unique fingerprint.

Cite this