Gold award

Singapore Science and Engineering Fair (SSEF) 2021
Sheng Jiarui, Dunmah High School
Supervisor: Adjunct A/Prof Nikolai Yakovlev
Optical Technique for Rapid and Quantitative Bacteria Detection

Bacteria detection plays an important role in different sectors like clinical diagnosis, food industry and environmental quality control. Portable, rapid and cost-effective methods are still challenging to achieve. This study investigates the performance of a novel optical technique for detecting bacteria in environmental water samples, specifically from cooling towers. The technique involves treating bacteria captured on filter membranes with a proprietor reagent that changes colour in contact with bacteria and measuring the colour change using a colorimeter. Orientations of filter, power sources and environmental conditions were found to be the parameters influencing the measurement of the colorimeter. The procedure of the test was evaluated and improved based on the problems observed. The test results of this colorimetric technique were compared with the standard plate count results, and a model of the correlation was presented.