A chemiresistive glucose sensor fabricated by inkjet printing

This paper proposes a simple and rapid fabrication of a glucose sensor based on inkjet printing method. A commercially available inkjet printer is used to print carbon nanotubes and polyaniline nanowires for patterning low sheet resistance electrodes and a chemiresistive glucose sensing area, respectively. Enzyme glucose oxidase, in conjunction with platinum nanoparticles were also incorporated into the chemiresistive sensor to generate a two-step catalytic process: in the first step, glucose is catalyzed by the oxidase to produce hydrogen peroxide as a byproduct, and in the second step, platinum nanoparticles catalyze hydrogen peroxide to produce hydroxide ions which causes a local pH change near the site of reaction. Since the conductivity of polyaniline is known to be pH-responsive, the polyaniline layer serves as a chemiresistive sensor to detect the H₂O₂ concentration which subsequently leads to the quantification of the glucose concentration. The developed inkjet-printed glucose sensor was able to achieve a detection limit of 2 mM and a good linear relationship between current measurements and glucose concentration was obtained. The results indicate that the proposed method to print a simple, rapid, and disposable glucose sensing device can lead to the development of an on-demand printable point-of-care diagnostic kit for glucose measurement.