With the latest microfluidic chip technology, the device can detect the virus in just 40 minutes from sampling to testing, compared to the currently-used polymerase chain reaction (PCR) technology which takes between 1.5 to 3 hours.
PCR technology is a molecular biotechnology used to amplify specific DNA fragments for the extraction of viral RNA, and the speed of temperature change is the key that determines the efficiency of the DNA’s amplification process, meaning the faster the temperature rises, the shorter the device can come up with a test result.
Unlike conventional large-scale PCR devices which use semiconductor to heat up testing samples, the team led by Prof. WEN Weijia from HKUST’s Department of Physics developed a novel silicon-based micro-heater module for the purpose. The micro-heater, which has lower thermal mass and a better thermal conductivity, could speed up temperature rises to around 30℃ per second from an average of 4-5℃ per second in conventional PCR devices, greatly reducing the detection time.
The detection device uses standard rapid testing tools such as those used for influenza: a quick screen is used to take a sample of the nasal cavity, which is then put into the analyzer to determine the result. Measuring just 33cm long, 32cm wide and 16cm high, the equipment set is light and portable, which is suitable for rapid on-site testing in places such as centers for disease control and prevention, customs, entry-exit inspection and quarantine departments, as well as nursing homes for the elderly. Each device is equipped with a microfluidic portable PCR analyzer, a pre-processing instrument, a bioassay chip and the novel coronavirus nucleic acid detection kits. It can test up to 8 samples simultaneously.