title: DNA-Assisted Exfoliation of Tungsten Dichalcogenides and Their Antibacterial Effect.
abstract: This study reports a method for the facile and high-yield exfoliation of WX2 (X = S, Se) by sonication under aqueous conditions using single-stranded DNA (abbreviated as ssDNA) of high molecular weight. The ssDNA provided a high degree of stabilization and prevented reaggregation, and it enhanced the exfoliation efficiency of WX2 nanosheets due to adsorption on the WX2 surface and the electrostatic repulsion of sugars in the ssDNA backbone. The exfoliation yield was higher with ssDNA (80%-90%) than without (2%-4%); the yield with ssDNA was also higher than the value previously reported for aqueous exfoliation (∼10%). Given that two-dimensional nanomaterials have potential health and environmental applications, we investigated antibacterial activity of exfoliated WX2-ssDNA nanosheets, relative to graphene oxide (GO), and found that WSe2-ssDNA nanosheets had higher antibacterial activity against Escherichia coli K-12 MG1655 cells than GO. Our method enables large-scale exfoliation in an aqueous environment in a single step with a short reaction time and under ambient conditions, and it can be used to produce surface-active or catalytic materials that have broad applications in biomedicine and other areas.
authors.affiliation: School of Electrical Engineering, Graphene Research Center, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea.
authors.forename: Gyeong Sook
authors.initials: GS
authors.lastname: Bang
authors.affiliation: Department of Biological Science and KI for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST) , Daejeon 34141, Republic of Korea.
authors.forename: Suhyung
authors.initials: S
authors.lastname: Cho
authors.affiliation: School of Electrical Engineering, Graphene Research Center, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea.
authors.forename: Narae
authors.initials: N
authors.lastname: Son
authors.affiliation: School of Electrical Engineering, Graphene Research Center, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea.
authors.forename: Gi Woong
authors.initials: GW
authors.lastname: Shim
authors.affiliation: Department of Biological Science and KI for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST) , Daejeon 34141, Republic of Korea.
authors.forename: Byung-Kwan
authors.initials: BK
authors.lastname: Cho
authors.affiliation: School of Electrical Engineering, Graphene Research Center, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea.
authors.forename: Sung-Yool
authors.initials: SY
authors.lastname: Choi
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D018011:Chalcogens / Q000494:pharmacology*; D004247:DNA / Q000737:chemistry*; D004926:Escherichia coli / Q000187:drug effects; D006108:Graphite; D057446:Hydrodynamics; D008826:Microbial Sensitivity Tests; D010316:Particle Size; D056951:Photoelectron Spectroscopy; D013056:Spectrophotometry, Ultraviolet; D013059:Spectrum Analysis, Raman; D014414:Tungsten / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D018011:Chalcogens; D006108:Graphite; D004247:DNA; D014414:Tungsten
keywords: DNA; antibacterial effect; aqueous exfoliation; nanosheet; tungsten dichalcogenides; two-dimension