Researchers at the Institute of Chemistry, University of São Paulo, São Paulo, Brazil have developed a method for the fabrication of electrochemical paper based analytical devices by direct laser scribing (LS-e-PAD) of a paperboard surface without the need for any chemical reagents or controlled atmospheric conditions. Pyrolysis of the paperboard using a CO2 laser enables the formation of a conductive, porous, non-graphitizing carbon material, which is composed of graphene sheets and aluminosilicate nanoparticles. The high conductivity and enhanced active/geometric area ratio suggest that this material is highly promising for the development of portable electrochemical devices.
Comparison of the performance of the LS-ePAD system with that of the conventional glassy carbon electrode and a commercial screen-printed (DropSens®) electrode using 5 mM mixture of potassium ferricyanide/ ferrocyanide solution as a redox probe reveals superior performance of the LS-ePAD system. Following their higher sensitivity and better reversibility, the utility of LS-ePAD as portable electrochemical sensors is explored for the detection of ascorbic acid and caffeic acid (important antioxidants present in food and dietary supplements) as well as in the forensic detection of picric acid (a military explosive).
The methodology of fabrication of LS-ePAD is simple, easily automated, and scalable for mass production. It is highly promising for the development of portable electrochemical devices with good reproducibility at low-cost.
T.S.N. Sankara Narayanan
For more information, the reader may kindly refer William R. de Araujo et al., Single-step Reagentless Laser Scribing Fabrication of Electrochemical Paper-based Analytical Devices, Angew. Chem. Int. Ed. 10.1002/anie.201708527
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