Scientists have released an open-source how-to guide which will allow anyone to turn their smartphone into a microscope that can detect dangerous microscopic particles in water.
Fluorescence microscopy is a technique used in medical diagnostics which allows researchers to find out a wide range of information from bodily fluid, tissues and other samples.
A team from Houston University has developed an attachment that converts any smartphone into a microscope capable of performing these sophisticated imaging tasks.
The parts of the device can all be created using a 3D printer and the resulting cartridge is designed to hold five LED lights and a standard 1 in x 5 in glass microscope slide.
Rather than shining light from above, as a tabletop microscope does, the light from the LEDs comes in from the side. This means it does not need to be adjusted, making it particularly easy to use.
The smartphone also needs to be fitted with an inexpensive inkjet-printed lens. Developed by the same team in 2015, the lens sticks to the phone’s existing camera lens.
The device is light-weight, weighing less than 27 g, and costs less than $20 to produce.
The team tested the device by comparing its accuracy to that of a standard lab microscope. The device was attached to a basic model smartphone.
Researchers prepared samples of liquid containing different species of bacteria and parasites, including Escherichia Coli, Giardia lamblia and Cryptosporidium parvum. They were then stained with standard florescence dye, so the particles showed up under fluorescence microscope.
Images were taken using both devices, and their quality compared using three widely used kinds of florescence microscopy.
Images from the smartphone device were produced in the field, to mimic how it would be used in practice.
The images taken by the smartphone and standard devices were comparable, though the resolution was slightly higher in those created from the tabletop microscope.
Using the smartphone attachment, the team were able to take autofluorescent images of chlorophyll in algae, monitor bacterial growth and identify the waterborne parasites, G. lamblia and C. parvum.
This technology has multiple uses. These devices have huge potential for tackling infectious disease on the ground in the developing world. While fluorescence microscopy is widely used in countries with advanced healthcare systems, it is not accessible to all.
The new open-source device is lightweight, costs less than $20 to produce, and allows analysis to take place without access to specialist equipment.
Wei-Chuan Shih, associate professor of electrical and computer engineering at the University of Houston, said: “We really hope anyone who wants to build it can. All the pieces can be made with a 3D printer. It’s not just something for the lab.”
Sung Y, Campa F, Shih WC. Open-source do-it-yourself multi-color fluorescence smartphone microscopy. Biomed Opt Express 2017; 8(11):5075-5086.