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Smartphone Device for Monitoring Water Quality Provide Fish Farmers With High-Tech and Low-Cost Solution

Engineers from the National University of Singapore (NUS) have developed a smartphone device able to detect the presence of harmful algae in just 15 minutes.

The team led by Assistant Professor Sungwoo Bae form the Department of Civil and Environmental Engineering at the NUS faculty of Engineering, invented a convenient and highly sensitive system that is able to produce results within minutes of the test to provide reports on water quality. This invention is powered wirelessly and could play a vital role in preventing the spread of harmful microorganisms in aquatic environments.

Results from the invention was first published online in the scientific journal Harmful Algae in July 2019.

Abrupt changes in water conditions such as unexpected surges in algae volumes can result in an increase in their associated toxins in water bodies, affecting water quality and cause unfavourable effects on aquatic ecosystems and environments of fish farms. An example could be drawn from the algae bloom in 2015 which wiped out more than 500 tonnes of fish in Singapore, resulting in loses of millions of dollars by some fish farmers.

Traditional ways of detecting algae have proven to be time consuming and would require specialized training and costly equipment to conduct the tests. “Currently, it can take a day or more to collect water samples from a site, bring them back to the laboratory for testing, and analyse the results. This long lead time is impractical for monitoring of algae blooms, as the management of contamination sources and affected waters could be slowed down,” explained Asst Prof Bae.

The invention is made up of three segments – 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. Cost of this device is less than US$220, excluding the smartphone and weighs less than 600 grams.

Trials were conducted by the research team with water samples collected from the sea and reservoirs. These samples were filtrated and spiked with specified amounts of four different types of toxin-producing algae. The four included, two types of freshwater algae C. reinhardtii and M. aeruginosa, and two types of marine water algae Amphiprora sp and C. Closterium.

Based on the tests run with the four types of algae, they observed an accuracy of 90 percent. Asst Prof Bae shared, “The combination of on-chip sample preparation, data capture and analysis makes our system unique. With this tool, water quality tests can be conducted anytime and anywhere. This new method is also very cost efficient as the microfluidic chip can be washed and re-used. This device will be particularly useful for fish farmers who need to monitor the water quality of their fishponds on a daily basis.”

The NUS research team are currently looking to commercialise their technology with industry partners and also develop a new microfluidic chip to be integrated with a modified version of the 3D-printed smartphone platform to detect the presence of foodborne pathogens.

This project was supported by the National Research Foundation Singapore through its Marine Science Research and Development Programme, and the Ministry of Education. [APBN]