All Inkjet Printing Sensor Device on Paper: for Immunosensors Applications

A novel flexible, low-cost and miniaturized paper-based transducer has been developed. It consisted of an array of three microelectrodes where, the working and counter microelectrodes were easily printed using a gold nanoparticle ink, whereas a silver nanoparticle ink is used to print a pseudo-reference microelectrode. Both inks are commercially available and can be sintered at low temperatures, starting already at 140 °C, which allows the use of paper substrates. Using the transducer developed an immunosensor against cortisol was fabricated. Microelectrode characterization showed an enhanced of the electrochemical active area due to high roughness of paper. Which infers a high sensitivity of microelectrodes. Moreover, the micro-sensor developed demonstrated to be highly sensitive toward cortisol in the concentration range of 5 to 20 ng/ml.