The prototype
smartphone-based detection system. (Photos courtesy of Professor Mei et al;
the images first
appeared in their paper in Biosensors and Bioelectronics.
(October 15, 2015) New
detection system could be used to find drugs, contaminants and bacteria
Take two things many of us have at home – paper and a
smartphone – and what do you get? Well, for one group of researchers in China
and Singapore, a reusable device for on-the-spot detection of pesticides.
Detecting molecules like pesticides in food or contaminants
in drinking water can be time-consuming and expensive, and the equipment can be
restrictively large. As a result, the detection of drugs, contaminants,
bacteria and proteins in samples is usually done in a laboratory. But as
healthcare moves from hospital to home and people need access to quick
diagnostics in the field, detection systems need to be made more portable.
Rising to the challenge, researchers at Hefei University of
Technology in Chinaand the National University of Singapore have developed
paper sensors that can be analyzed using an Android program on a smartphone –
an almost pocket-sized device that could detect chemicals like pesticides
rapidly and cheaply. Their study, published in Biosensors and Bioelectronics,
describes the new approach they have taken to making a system that can detect
low concentrations of pesticide – and potentially any substance – in a sample.
Hacking consumer
technology
According to telecommunications company Ericsson, there could
be more than 6 billion smartphones in use by 2020 – almost one for every person
on the planet. Smartphone technology is portable, accessible and relatively
cheap so the researchers aimed to tap into that for their detection system.
“Since detectors are usually big, it was important that we
could develop a smaller unit that was powerful enough to detect small
concentrations of the pesticide,” said one of the authors of the study, Dr.
Qingsong Mei, an Associate Professor in the School of Medical Engineering at
Hefei University of Technology in China.
To make the detector, the researchers had to develop three
components: nanoparticles to detect the pesticide and emit a fluorescent signal
on the paper, a 3D-printed piece of equipment made of a smartphone attached to
a mini-laser, an optical filter and a mini-cavity, and a piece of software that
runs on Android.