Abstract:
This study focuses on the design and fabrication of a hydrogel based pH sensor array for physiological applications. pH levels in the physiological environment is an important parameter in assessment of the normal functioning of the body. pH sensors such as pH glass electrodes, fiber optic pH sensors and sensors made from metal oxide has many limitations. To address these limitation, there is a need for planar, biocompatible, flexible and point of care pH sensor array that can conform with body organs and provide a map of pH levels. The development of this conductometric pH sensor array has been carried out on the basis of measurement of the conductance of a pH-responsive composite (Chitosan/Gelatin) hydrogel. The final design of the pH sensor array is dependent on the electrode density. Electrode density in a matrix is calculated and design is made using Proteus design suite 8.1 software. For fabrication copper conductive layer on a flexible polyimide substrate is used. Conductometric tests are carried out on pH sensor array and results show good sensitivity and resolution in the physiological pH range (pH 4 - 10). Sensor array is also able to provide a map of pH level for physiological monitoring.
