pHishlet: Development of pH-Sensitive Bio-Responsive Bracelet with Support from Tilapia (Oreochromis) Fish Skin Mucus for Water Quality Monitoring

Rural and low-resource communities are still challenging themselves to monitor the quality of water due to high costs and lack of access to standard testing instruments. This paper designed and validated the pHishlet bio-bracelet, a simple, wearable water quality sensor, which is a low-cost device made from Tilapia (Oreochromis) fish skin mucus-based pH-sensing. It was aimed at evaluating its performance, color change response, response time, optimum mucus ratio, and its general accuracy in the presence of seawater, river water, and pool water. Bio-mixture was prepared using extracted fish mucus, a universal indicator pH and glycerol and integrated within a resin bracelet. The experiment entailed the placement of the bracelet in samples of water of various PH ranges and comparing the findings with a digital pH meter. The findings revealed that the bio-bracelet generated clear changes in color that were consistent and referred to the universal pH scale with full accuracy. Whereas the response time was changed with the influence of the environmental factors such as the Total Dissolved Solids (TDS) and temperature, the accuracy was not affected. An increased mucus concentration resulted in clearer and more constant color changes, which determined the best formula. The statistical analysis showed that there were significant differences in the response time among the various types of water, but the reliability of detection did not change significantly. Based on the results, the fish skin mucus can be used as an effective and sustainable biosensing material. This indicates the possibility of using the pHishlet bio-bracelet as a convenient community-based water quality monitoring and environmental education resource.