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The Journal of Materials Chemistry A published an expression of concern regarding the reliability of data in an article titled "Preparation of reduced graphene oxide–Ni(OH)2 composites by electrophoretic deposition: application for nonenzymatic glucose sensing." The Royal Society of Chemistry has requested the University of Lille to investigate the matter, and the expression of concern will remain until conclusive evidence is obtained. The article was authored by Palaniappan Subramanian, Joanna Niedziolka-Jonsson, Adam Lesniewski, Qian Wang, Musen Li, Rabah Boukherroub, and Sabine Szunerits. [Extracted from the article]

General properties of the recently observed screening of the van der Waals (vdW) attraction between a silica substrate and silica tip by insertion of graphene are predicted using basic theory and first-principles calculations. Results are then focused on possible practical applications, as well as an understanding of the nature of vdW attraction, considering recent discoveries showing it competing against covalent and ionic bonding. The traditional view of the vdW attraction as arising from pairwiseadditive London dispersion forces is considered using Grimme's "D3" method, comparing results to those from Tkatchenko's more general many-body dispersion (MBD) approach, all interpreted in terms of Dobson's general dispersion framework. Encompassing the experimental results, MBD screening of the vdW force between two silica bilayers is shown to scale up to medium separations as 1.25 de/d, where d is the bilayer separation and de is its equilibrium value, depicting antiscreening approaching and inside de. Means of unifying this correlation effect with those included in modern density functionals are urgently required. [ABSTRACT FROM AUTHOR]

A sensitive and stable non-enzymatic sensing platform for D-glucose based on a reduced graphene oxide (rGO) matrix modified with Ni(OH)[sub 2] nanostructures was established. The sensing matrix was fabricated in one-step through an electrophoretic deposition approach. It is based on the mixing of negatively charged graphene oxide (GO) with nickel ions resulting in a positively charged composite making cathodic electrophoretic deposition possible. The thickness of the resulting rGO/Ni(OH)[sub 2] matrix deposited on Au could be controlled by varying the time of electrophoretic deposition. The rGO/Ni(OH)[sub 2] matrix was characterized by X-ray photoelectron spectroscopy, Raman spectroscopy and cyclic voltammetry. The rGO/Ni(OH)[sub 2] electrodes exhibited excellent electrocatalytic behaviour towards glucose oxidation in alkaline medium. The response current of the sensor is linear to glucose concentrations from 15 mM to 30 mM with a sensitivity of 11.4 ± 0 mA cm[sup- 2] mM[sup -1]. The interface was much more stable than drop-cast films. These results pave the way for electrophoretic deposition as a competitive alternative over drop-casting for the fabrication of rGO modified interfaces. [ABSTRACT FROM AUTHOR]

Poly-ϵ-caprolactone (PCL) is a biodegradable polyester that has received great attentions in clinical and biomedical applications as sutures, drug delivery tool, and implantable scaffoldmaterial. Silica aerogel is amaterial composed of SiO2that has excellent physical properties for use in drug release formulations and biomaterials for tissue engineering. The current study addresses a composite of silica aerogel with PCL as a potential bone scaffold material for bone tissue engineering. The biocompatibility evaluation of this composite indicates that the presence of silica aerogel effectively prevented any cytotoxic effects of the PCL membrane during extended tissue culture periods and improved the survival, attachment, and growth of 3T3 cells and primary mouse osteoblastic cells. The beneficial effect of silica aerogelmay be due to neutralization of the acidic condition that develops during PCL degradation. Specifically, it appears that silica aerogel to PCL wt/wt ratio at 0.5 : 1 maintains a constant pH environment for up to 4 weeks and provides a better environment for cell growth. [ABSTRACT FROM AUTHOR]