Graphene/SiO2 nanocomposites: The enhancement of photocatalytic and biomedical activity of SiO2 nanoparticles by graphene

Abstract

ABSTRACT:The exceptional conducting nature of graphene makes it a viable candidate for enhancing the effectiveness of photocatalytic and biomedical nanomaterials. Herein, the immobilization of monodispersed silicon dioxide (SiO2) nanoparticles on multiple graphene layers is demonstrated for intercalation of graphene nanoplatelets (GNPs). Interestingly, the loading of graphene nanoplatelets with SiO2 nanoparticles enhances the photocatalytic efficiency from 46% to 99%. For biomedical applications, it is found that 75% of Gram positive and 50% of Gram negative bacteria have been killed, hence bacterial proliferation is significantly restricted. Further, the cytotoxicity study reveals that the synthesised nanocomposites are non-toxic for both normal (HCEC) and cancerous (MCF-7, HEp-2) cell lines which signifies their potential as carriers for drug delivery. The prepared nanocomposites with controlled amount of carbon in the form of graphene can be employed for photocatalysis based waste water remediation, biomedicine and nano drug delivery.

High‐pressure torsion of SiO2 quartz sand: Phase transformation, optical properties, and significance in geology

“…The low photocatalytic activity of HPT‐processed SiO 2 is naturally due to its large band gap and due to the electronic configuration of silicon 38–40 . However, a possible approach to enhance the photocatlytic activity of SiO 2 in future is increasing the concentration of oxygen vacancies more significantly by the application of HPT to doped SiO 2 under higher processing temperatures or by processing the SiO 2 ‐based composite systems 28–34 …”

“…SiO 2 quartz, which is largely available in the earth in the form of sand and minerals, has been widely used in a variety of industrial fields, ranging from ceramics to optics through microelectronics 25 . SiO 2 quartz was rarely used as a photocatalyst on its own, although several reports appeared in the literature on the preparation of composites with SiO 2 as a catalyst support for use in the photocatalytic dye degradation 28–34 . Photocatalysis is considered as an effective technology for treating toxic and dangerous waste by combination of photochemical process and catalysis 35–37 .…”

Manganese-Doped Cerium Oxide Nanocomposite Induced Photodynamic Therapy in MCF-7 Cancer Cells and Antibacterial Activity

“…The free radicals ·O 2− and ·OH produced in the reactions can react with organic substances inside bacterial cells to produce bacterial toxins, leading to the death of the bacteria. In particular, the generated H 2 O 2 easily penetrates the cell membrane and kills the bacteria [11, 12, 17, 20].…”

“…In this study, we will explore new strategies to combat breast cancer and the inhibition of growth of various bacterial infections. Mn-doped cerium oxide is an excellent candidate for applications in nanobiology and regenerative nanomedicine in the in vitro cell line and zone of inhibition (ZOI) and is useful for optical density measurements of various bacteria [17].…”

Understanding the driving forces of camptothecin interactions on the surface of nanocomposites based on graphene oxide decorated with silica nanoparticles

“…The main nanocarriers include graphene oxide (GO), 22-24 mesoporous silica nanoparticles (MSNs) [25][26][27] and a new family of nanocomposites based on graphene oxide decorated with silica nanoparticles (GO-MSNs). 28,29 Graphene oxide is a two-dimensional carbon nanomaterial comprising regions of carbon atoms with sp 2 hybridization and sp 3 carbons associated with oxygenated functional groups, including carboxylic acid, ketone, aldehyde, epoxide, hydroxyl and lactol groups. 30 This material intrinsically has interesting characteristics, such as good water dispersibility, high mechanical strength and a signicant theoretical surface area (2630 m 2 g À1 ).…”