Cao Aoneng

Solution-Processable,Highly Conductive,Permanently Rippled Graphene Sheets

The single atom thick sp 2 carbon structure of graphene gives rise to its unique properties and potential applications. However, one serious obstacle for its application is that graphene is prone to aggregate in suspension and gradually stack into graphite. Here, we report a novel approach to solve this problem. The basic idea is to introduce sp 2 carbon nano-islands on the graphene sheets that act as permanent ripples to prevent the stacking and graphitization of graphene and make it easy to re-suspend. Unlike most functionalization methods, this approach avoids the introduction of heteroatoms. Thus, it does not deteriorate the structure and change the properties of graphene. The carbon-rippled graphene has a remarkable electronic conductivity of ~65000 S·m - 1 , and can be readily suspended in solvent.

Determination of protein concentration from CD spectrum

Protein concentration can be determined from its circular dichroism(CD) spectrum and from programs that calculate protein secondary structure content from CD. The method established was successfully applied to lysozyme and a de novo designed peptide with a standard error of about 5%, which is comparable to concentrations determined from an estimated extinction coefficient. This procedure is widely applicable in protein and peptide samples.