A new device, developed by researchers at the University of California, can transform a simple mobile phone into a microscope with the ability to detect E. coli bacteria in foods or liquids.
The scanner can be attached to most mobile phones with an inbuilt camera. As there are currently more than 5 billion mobile phones worldwide, of which 70 per cent in developing countries, where E. coli poses a major threat, the creators hope the cheap and simple scanner device will become popular and, potentially, save lives.
E. coli is passed on to humans through the consumption of contaminated goods, like raw vegetables, milk and raw or undercooked meat products. Many strains are not damaging to human health, but others, such as enterohaemorrhagic E. coli can lead to a very harmful disease.
The instrument consists of glass capillary tubes with LED lights on both ends. Attached to the sides are E. coli antibodies that trap any E. coli bacteria present in a sample. Then, secondary antibodies and quantum dots are added to the capillaries. The LED lights cause the quantum dots to emit a fluorescent light that is captured by the phone camera and shows concentrations of the E. coli bacteria.
Lead researcher Hongying Zhu and his team were able to detect low concentrations of E. coli in samples of water and milk. There are plans to further develop the device to enhance its capabilities to recognise different types of bacteria. Detailed findings were published in the Royal Society of Chemistry journal, Analyst.