The infection will be detected by a smartphone with a thermocup

The smartphone was adapted for the diagnosis of infections by the DNA of the pathogen

Oleg Lischuk, N+1

American scientists have developed a mobile device connected to a smartphone for molecular express diagnostics of infectious diseases, which does not need special training of a biological sample, a source of electricity and qualified personnel. The work report was accepted for publication in the journal Sensors and Actuators B (Liao et al., Smart cup: A minimally-instrumented, smartphone-based point-of-care molecular diagnostic device).

Appearance of the device and the thermoelectric element
(picture from the article in Sensors and Actuators)

The principle of operation of the device, created at the University of Pennsylvania, is based on loop isothermal amplification (LAMP) of nucleic acids of the pathogen. This method is much more sensitive than immunochromatographic diagnostics (it is used in several experimental mobile systems), and, unlike PCR, does not require cyclic temperature changes.

The body of the new device is a conventional vacuum thermocup. Inside it is a microfluidic LAMP chip that enzymatically increases the concentration of the pathogen's genetic material in a blood sample. It operates at a constant temperature of 60-65 degrees Celsius. The necessary heating is provided by a thermoelement made of an alloy of magnesium with iron, which, upon contact with water, enters into an exothermic reaction. The constant temperature is maintained by the phase-changing material PureTemp 68, melting at 68 degrees Celsius.

Visualization of LAMP results in real time is carried out by recording the fluorescence of the sample. To do this, the researchers mounted an excitation filter and an emission filter in the smartphone holder cover (it was printed on a 3D printer), which allow you to use the flash and the smartphone camera. In the experiment, scientists were able to identify the DNA of the herpes simplex virus type 2 in a sample containing only one hundred viral particles.

Due to the simplicity of the device and the absence of the need for an external power source, rapid diagnosis of infections with its help can be carried out in the field. This is especially important when providing medical care in hard-to-reach areas and working in epidemic hotbeds, the developers note. In addition, the new device is much cheaper than analogues based on PCR and other diagnostic methods.

Portal "Eternal youth" http://vechnayamolodost.ru  03.03.2016