Remember looking for the nearest payphone and scrambling for change or having to wait by the home phone when expecting an important call? With today's smartphones, such experiences are but distant memories. Now, we can effortlessly send and receive information anytime, anywhere. Given the transformative power of mobile technologies, imagine the possibilities if typically lab-based scientific equipment became portable too.
Take, for instance, the spectrophotometer, a quintessential piece of lab equipment used for measuring the concentration of substances like proteins and nucleic acids in solution. Spectrophotometers are bulky, expensive machines that need a constant power source, which restricts their use to a lab setting.
Freeing the spectrophotometer from the four walls of the lab opens up a whole new world of scientific prospects: testing for environmental contaminants in the field, mobile diagnostic units, food safety testing and more. To make this a reality, a team of researchers led by Samuel Gan, Principal Investigator at the Antibody and Product Development Lab of A*STAR’s Experimental Drug Development Centre (EDDC) and Bioinformatics Institute (BII), sought to develop a fully portable smartphone-dependent spectrophotometer.
Central to the team’s design focus was affordability, to ensure that their innovation would be accessible even to low-resource communities. With this in mind, the researchers selected only off-the-shelf electronic parts, including wires, switches and batteries to create their unit. Even the highly-specialized LED lamps, components that directly influence the spectrophotometer's accuracy, were commercially sourced. Meanwhile, the device’s inner workings were driven by an Arduino board that serves as the ‘brain,’ calculating concentration values based on input light signals.
The team then designed a 3D-printed outer shell keeping in mind factors like the heat emitted during the machine's operation, wire paths and compatibility with the commonly used containers housing the liquid samples. Finally, they developed their Android app to control the mobile spectrophotometer, allowing users to collect data and re-calibrate the device with their smartphone—no desktop computers needed!
When put to the test, the portable device delivered slightly lower limits of protein measurements than its commercial counterpart but showed superior higher ranges when quantifying nucleic acids. According to Gan, these performance differences underscores the need for future software optimization to boost the device's range. Nevertheless, the mobility and accessibility of the team's invention mark a significant milestone in the prospect of mobile lab platforms.
“Once the DIY movement picks up, we envision such self-assembled devices to disrupt and free-up the spatial-bound nature of biomedical research,” said Gan, adding that portable spectrophotometers also have the potential to revolutionize point-of-care patient screening and diagnostics.
The A*STAR-affiliated researchers contributing to this research are from the Experimental Drug Development Centre (EDDC) and Bioinformatics Institute (BII).