A team of engineers from the National University of Singapore (NUS) has developed a highly sensitive system that uses a smartphone to rapidly detect the presence of toxin-producing algae in water within 15 minutes. This invention can generate test results on-site, and findings can be reported in real-time using the smartphone’s wireless communications capabilities.
Conventional methods of algae detection and analysis are time consuming, and require specialised and costly equipment, as well as skilled operators to conduct water sampling and testing. One approach is to test for the presence of chlorophyll using complex instruments that cost more than S$3,000 (US$2,200). Another common method is to carry out cytometric and image analysis to detect algal cells – this method involves equipment that cost more than S$100,000 (US$73,000).
The portable and easy-to-use device developed by NUS costs less than S$300 (US$220) – excluding the smartphone – and weighs less than 600 grams. The test kit is also highly sensitive, hence only a small amount of water sample is needed to generate reliable results.
The new NUS invention comprises three sections - a microfluidic chip, a smartphone, and a customisable 3D-printed platform that houses optical and electrical components such as a portable power source and an LED light.
The chip is first coated with titanium oxide phthalocyanine, a type of photoconductive polymer-based material. The photoconductive layer plays the important role of guiding water droplets to move along the chip during the analysis process.
The research team is currently in discussion with industry partners to commercialise their technology.
The NUS researchers are also developing a new microfluidic chip that can be integrated with a modified version of the current 3D-printed smartphone platform to detect the presence of foodborne pathogens such as salmonella and other infectious pathogens.