Novel pH Sensors

Project Outline:

The measurement of pH value is an important research topic in various fields like; water quality monitoring, blood pH level monitoring, clinical diagnosis and environment monitoring. The most commonly used method to sense pH is the conventional glass pH electrode. These glass electrode shows many advantages, such as; Nernstian sensitivity, long-term stability, high ion selectivity and wide operating range. However, they also have key disadvantages including, mechanical fragility, need for wet storage, large size, limited shape and high cost, which makes them impractical for some applications such as miniature pH sensor for capsule endoscopy and ambulatory esophageal pH monitoring.Therefore, various metal oxides have been investigated for use as pH sensors instead of the glass electrode, because of their insolubility, stability, mechanical strength and possibility of miniaturization. However, the main drawback of metal oxide pH sensors is interference caused by oxidizing and reducing agents in the sample solutions.

This project involves developing solid-state potentiometric pH sensors using metal oxides and nitrides, such as ruthenium metal oxide (RuO2) and titanium nitride (TiN) by manufacturing thin-films of these compounds using radio frequency magnetron sputtering using various conditions and then investigating the optimized thin-films for use as pH sensors.

If successful, the optimized material will be used to construct a solid-state pH sensor using an appropriate reference electrode and this sensor will potentially be able to use in lab-on-chips and pH sensor capsules which was a shortcoming for glass electrodes.

Desired skills: The research student is expected to possess a basic knowledge of materials science and electrochemistry with undergraduate studies and skills in chemistry, chemical engineering or physics.

Project Area: Materials science and electrochemistry

Supervisor(s):  Professor Kamal Alameh and Dr Magdalena Wajrak

Project level: Masters, PhD

Funding: Applicant should apply for ECUHDR or RTP Scholarship

Start date: Semester 1, 2021