RESUMO
In this study, the effects of magnesium (Mg) doping and Ammonia (NH3) plasma on the pH sensing capabilities of InGaZnO membranes were investigated. Undoped InGaZnO and Mg-doped pH sensing membranes with NH3 plasma were examined with multiple material analyses including X-ray diffraction, X-ray photoelectron spectroscopy, secondary ion mass spectroscopy and transmission electron microscope, and pH sensing behaviors of the membrane in electrolyte-insulator-semiconductors. Results indicate that Mg doping and NH3 plasma treatment could superpositionally enhance crystallization in fine nanostructures, and strengthen chemical bindings. Results indicate these material improvements increased pH sensing capability significantly. Plasma-treated Mg-doped InGaZnO pH sensing membranes show promise for future pH sensing biosensors.
RESUMO
In this study, the effect of post-deposition tetrafluoromethane (CF4) plasma treatment on the physical and electrical characteristics of an In2TiO5 based electrolyte-insulator-semiconductor (EIS) sensor was investigated. Post-deposition CF4 plasma treatment typically improved the crystalline structure and repaired dangling bonds at the grain boundaries. We used the newly fabricated device to detect several ions, such as sodium and potassium, which are essential for many biological processes. The as-deposited and CF4 plasma treated In2TiO5 sensing window with an EIS structure was also able to detect the pH of a solution, different alkali ions (Na+ and K+), glucose, and urea. The sensing membrane after a 60-sec CF4 plasma treatment displayed improved biosensing characteristics, such as higher sensitivity (59.64 mV/pH), better drift rate, and a smaller hysteresis voltage of approximately 0.424 mV/h. The In2TiO5 sensing membrane treated with CF4 plasma is a promising material for use in EIS biosensing applications.
