Graphene platforms for the detection of caffeine in real samples
- Weslie Yu Heng Khoo, Martin Pumera, Alessandra Bonanni*
The analysis of food components is of high importance due to food safety and security. Here the electrochemical detection of caffeine was performed on different chemically modified graphene (CMG) surfaces carrying diverse amount of defects and oxygen functionalities. The analytical performances of graphite oxide (GPO), graphene oxide (GO), and electrochemically reduced graphene oxide (ERGO) were compared for the first time for the detection of caffeine. It was found that ERGO showed the most favourable analytical parameters, such as lower oxidation potential, sensitivity, linearity and reproducibility of the response. ERGO was then used for the analysis of real samples. Caffeine levels of soluble coffee, teas and energetic drinks were measured without the need of any sample pre-treatment. Our findings are very important to gain more insight into the applicability of different graphene materials to real samples for sense-and-act analysis. (C) 2013 Elsevier B.V. All rights reserved.
MoS2 versatile spray-coating of 3D electrodes for the hydrogen evolution reaction
The capacitance and electron transfer of 3D-printed graphene electrodes are dramatically influenced by the type of solvent used for pre-treatment