pH Measurement Using Titanium Dioxide Nanoparticles Thin Film Based Sensors

Abstract

Optimization gap size and integration of TiO2nanoparticles thin film produce a sensitive sensor device. Sol-gel spin coated TiO2nanoparticles thin film is coated on a conventional fabricated IDEs with gap sizes of 7 μm, 10 μm, 14 μm and 17 μm which is then validated through electrical characterization. I-V characteristics of without and with TiO2thin film of various gap sizes are subjected to pH test are then plotted to describe the resistance of the devices and correlate with the sensitivity measurement. Sensing devices show that devices with larger spacing and greater pH values have higher current. On the other hand, integration of TiO2thin film reduced the resistance of devices. Among the four gap sizes, 7 μm gap sized device is the most sensitive one due to the tremendous difference after small amount of pH dropped on surface, thus lowering the detection limit.