Cell surface morphology mimicking nano-bio platform for immune cell stimulation.

Studying the complex realm of cellular communication and interactions by fluorescence microscopy requires sample fixation on a transparent substrate. To activate T cells, which are pivotal in controlling the immune system, it is important to present the activating antigen in a spatial arrangement similar to the nature of the antigen-presenting cell, including the presence of ligands on microvilli. Similar arrangement is predicted for some other immune cells.

Effect of Triton X-100 on the Activity and Selectivity of Lipase Immobilized on Chemically Reduced Graphene Oxides.

The effect of support hydrophobicity on lipase activity and substrate selectivity was investigated with and without Triton X-100 (TX-100). Lipases from (TL) and (QLM) were immobilized on graphene oxide (GO) and a range of chemically reduced graphene oxides (CRGOs) with different levels of surface hydrophobicity. Activity assays using 4-hydroxy--propyl-1,8-naphthalimide (NAP) esters of varying chain lengths (NAP-butyrate (NAP-B), NAP-octanoate (NAP-O), and NAP-palmitate (NAP-P)) showed that the activity of immobilized QLM and TL decreased by more than 60% on GO and 80% on CRGO (2 h), with activity decreasing further as surface hydrophobicity of the CRGOs increased.

Solvent Effect on Supramolecular Self-Assembly of Chlorophylls a on Chemically Reduced Graphene Oxide.

Solvent plays an important role in the surface interaction of molecules. In this study, we use "chlorophyll a", an archetypical molecule, to investigate its supramolecular self-assembly with chemically reduced graphene oxide in three different types of solvents: polar protic, polar aprotic, and non-polar. It was observed that only a polar protic solvent that can donate protons facilitates the hydrogen bonding between chlorophyll a and chemically reduced graphene oxide nanosheets in a hybrid system.

Quantifying Graphene Oxide Reduction Using Spectroscopic Techniques: A Chemometric Analysis.

The surface chemistry of graphene oxide (GO) can be modified by the chemical reduction of oxygen-containing groups using L-ascorbic acid (L-AA). Being able to "tune" the surface hydrophobicity of GO in a controlled manner, with a well-defined level of reduction, provides a valuable tool for understanding and controlling interactions with hydrophobic surfaces. Numerous analytical and chemical methods have been used to determine the extent of reduction in chemically reduced graphene oxide (CRGO) samples.

Controlling enzyme function through immobilisation on graphene, graphene derivatives and other two dimensional nanomaterials.

Robust enzyme immobilisation methods that preserve enzyme activity while enabling enzymes to be recovered and reused multiple times have important applications in biocatalysis. However, immobilisation can change the functionality of enzymes, both in terms of their level of activity and their selectivity. These changes in activity are unpredictable and at present cannot be controlled, but if fully understood at a fundamental level could offer the opportunity to create highly targetted enzyme systems for specific applications.