Electrochemical Portable Mini-Potentiostat for Graphene-Carbon Paste Electrochemical Sensor

This research studied about mini-potentiostat to analyze minimal reagent consumption for graphene electrochemical sensor of lab on a chip. Mini-potentiostat was designed with electronics circuits and was fabricated by using integrated circuit and was controlled with microcontroller. For design, mini-potentiostat was designed to test graphene electrochemical sensor at the end of T-junction electrowetting on dielectric (EWOD) as digital microfluidic microchip which used for merging droplets to move the droplets to three detectors of the sensor for analysis. Three detectors consist of a screen-printing electrode which are graphene-carbon working and counter electrodes, and a silver/silver chloride reference electrode. For calibration, the board level potentiostatic circuit with Arduino Uno R3 was calibrated to test for electrochemical sensor with resistors that were varied from 28, 43, 62, 82 kΩ. For analysis, the mini-potentiostat was demonstrated to test for the electrochemical detectors for minimal reagent consumption with potassium hexacyanoferrate and hydrogen peroxide. The concentration of reagent was varied from 2, 4, 6, 8, and 10 mM and 20, 40, 60, 80, and 100 μΜ for hexacyanoferrate and nicotinamide adenine dinucleotide, respectively. The results achieved satisfied accuracy for this application request.