A Flexible Copper Based Electrochemical Sensor Using Laser-Assisted Patterning Process

A novel impedance based electrochemical sensor was fabricated on a flexible polyethylene terephthalate (PET) film to detect various bio/chemicals. The flexible electrochemical sensor was developed using a thin metallic copper foil tape (electrodes) and PET (substrate). The copper tape was attached to the PET substrate and a two-electrode device configuration, including the working and circular electrodes, was created by patterning and cutting the copper on the PET substrate using a laser-assisted patterning process. The capability of the fabricated sensor was investigated by performing electrical impedance spectroscopy (EIS) for the detection of a heavy metal: cadmium sulfide (CdS). An impedance change of 69.9±3.4%, 77.8±2.1 %, 92.1±1.0% and 99.5±0.2% was obtained as the concentration of the CdS increased from 100 pM to 100 nM to 100 f.1M to 100 mM, respectively. The EIS based response demonstrated the detection capability of the sensor for concentrations as low as picomolar (pM) levels and was also able to successfully distinguish among varying concentrations (pico, nano, micro and milli) of CdS. The fabrication of the sensor and its EIS based response towards CdS has been analyzed and is presented in this paper.