Under the epidemic situation, in addition to continuing to strengthen the research and development of vaccines and drugs, it is also very important to improve personal health and environmental health management. Accurate and convenient virus detection methods are critical. Recently, the Hong Kong Polytechnic University (hereinafter referred to as "PolyU") developed a portable new crown virus nucleic acid detector that can detect up to four samples at the same time, and can establish a positive sample within 25 minutes, while the entire test is completed in about 40 minutes, and the test results can also be identified by the naked eye.
"The detector can be used in airports, quarantine facilities, clinics, ports, etc., to strengthen personal and environmental hygiene management, but also to help relevant institutions quickly formulate prevention and control strategies and reduce the risk of infection in the community." The team leader said in an exclusive interview with Nandu reporter that the detector can be put into use, but there is no plan for mass production at this stage. The team is also in contact with an international testing and certification body for further market-oriented research cooperation.
Prof Ruheng Zhao, Vice-President of PolyU hong Kong (centre), Professor Ip She-ping of the Department of Medical Technology and Informatics (first from left) and Associate Professor Lee Ming Hung of the Department of Biomedical Engineering (first from right) present the "Portable COVID-19 Detector". Image source: The official website of the Hong Kong Polytechnic University.
Up to four samples are tested simultaneously
The test is completed in about 40 minutes
According to PolyU's official website, in 2020, PolyU's interdisciplinary research team received more than HK$2.7 million in grants from the Health and Medical Research Fund to carry out research on portable COVID-19 detectors (hereinafter referred to as "detectors"). Over the past year and a half, the team has successfully conducted accurate COVID-19 tests using reverse transcription thermostatic ring amplification (RT-LAMP) and gold nanoparticles (as nucleic acid amplification displays). Clinical sample test results are in full agreement with reverse transcription polymerase chain reaction (RT-PCR) criteria.
The detector can place up to six samples simultaneously, and up to four samples can be detected simultaneously, except for two positive and negative control samples. Once the sample is taken, it can be tested on site using a detector without having to send the sample back to the lab. The instrument creates a constant temperature of 65 degrees Celsius, and its built-in optics detect the precipitation of gold nanoparticles (positive samples will precipitate, while negative samples will remain scattered).
The "Portable Covid-19 Detector" is lightweight, weighing only about 2.4 kg, with a volume of 21 cm× 21 cm× 10.5 cm, equipped with a built-in power supply. Image source: The official website of the Hong Kong Polytechnic University.
The relevant data is instantly transmitted to the mobile phone via Bluetooth, and the software analyzes and displays the results. Between 10 and 20 minutes, if the optical data displayed on the screen shows an upward trend, it means that the sample is positive, and the faster the data rise, the higher the virus content of the sample, which means that within 25 minutes, the positive sample can be confirmed, and the entire test is completed in about 40 minutes, and the test results can also be identified by the naked eye.
"Thanks to the trust placed in PolyU by the Food and Health Bureau of Hong Kong, through the funding of the Health Research Fund, PolyU has been able to exert its interdisciplinary strength, fully support and cooperate with the Government's anti-epidemic efforts, and transform the research results into application for the benefit of the community." PolyU Vice-Chancellor (Research and Innovation) Prof Ruheng Zhao said.
It can detect human and environmental samples
Helps reduce the risk of infection in the community
Leading the study was led by Professor Ye Sheping, Professor and Head of the Department of Medical Technology and Informatics at PolyU, who said that the key to the research lies in the gold nanoparticle display agent, which can achieve 100% sensitivity and specificity through the detector developed by the team, which is in line with the current "gold standard" for nucleic acid detection of the new crown virus.
Another feature of the detector is that it can be operated in an environment outside the laboratory, and it is equipped with a built-in power supply, which can be used after charging, and can complete the entire inspection procedure on the spot after sampling. Team member Dr. Li Minghong, Associate Professor and Deputy Head of the Department of Biomedical Engineering, PolyU, explained that the environmental sample tests made by the team have successfully shortened the detection time, without the need to use large nucleic acid detection instruments in the laboratory, and accurate nucleic acid detection has been achieved in the small detector. Even if the virus volume is low, accuracy is not affected.
Li Minghong said that the detector can be used to detect human and environmental samples, can also detect different viruses and bacteria (with corresponding primers), and the testing cost is relatively low compared to RT-PCR. The team is about to transfer the research results and cooperate with the industry to popularize the technology in the community, especially in some places where accurate test results need to be obtained in a short period of time, which will help relevant institutions to formulate prevention and control strategies and reduce the risk of infection in the community.
Recently, the head of the research team, Professor and Head of the Department of Medical Technology and Informatics at PolyU, Professor Ye Sheping and his team were interviewed by Nandu reporters to reveal the story behind the development of portable new coronavirus nucleic acid detectors.
dialogue
Combine the right technology with a lightweight design, but with a high degree of precision
Nandu: What was the opportunity to start this research? How should I consider researching a portable COVID-19 tester?
Ye Sheping: Dr. Minghong Li and I have been engaged in genetic testing research for many years, and the two met at PolyU more than a decade ago and collaborated on different research projects, including nucleic acid testing of gold nanoparticles. In 2016, one of Dr. Lee's undergraduate students used the first generation of portable virus detectors as his graduation work. Subsequently, with the support of polyU's Industrial Centre, Dr Lee developed a second-generation portable virus detector with better function and structure.
In 2017, Dr Lee and I began working with the Agriculture, Fisheries and Conservation Department of the Government of the Hong Kong Special Administrative Region to develop portable testing instruments for the detection of avian influenza viruses. During this research period, in response to the COVID-19 pandemic, the two of us decided to use the results of our past research to shift our focus to testing for COVID-19.
Nandu: Can you tell us about the highlights and breakthroughs of this study?
Ye Sheping: Although the reverse transcription thermostatic ring amplification method (RT-LAMP) used in the portable new coronavirus detector (detector) is not a new technology, the polytechnic team successfully combined it with its self-developed gold nanoparticles (as a nucleic acid amplification display agent) to detect the new crown virus, and the results obtained were highly accurate - its sensitivity and specificity reached 100%, which was fully consistent with the reverse transcription polymerase chain reaction (RT-PCR) standard.
Testing with a detector can confirm a positive sample in as little as 25 minutes, and the entire test is completed in about 40 minutes. One of its characteristics is that its test results can be identified by the naked eye - just observe the precipitation of gold nanoparticles to obtain the test results (positive samples will precipitate, negative samples will remain scattered). The relevant data will also be transmitted to the mobile phone in real time, and the personnel can view the test results in real time.
Gold nanoparticles from a positive sample (right) will precipitate, while a negative sample (left) will remain dispersed and the results will be recognizable by the naked eye. Image source: The official website of the Hong Kong Polytechnic University
Another breakthrough point is the portable design of the instrument, equipped with a built-in power supply, and can be used in any application after charging. In the past PCR test, the sample needed to be sent back to the laboratory for processing after sampling, and it took as little as 2 hours to get the results regardless of the transit time. PolyU's portable detectors can be operated outside the laboratory, which means that after sampling on the spot, the test can be carried out in real time and the results can be obtained in a short period of time.
Nandu: What difficulties were encountered in the research and development process, and how were they solved later?
Ip: The PolyU team understands that the current PCR testing takes a long time and needs to be combined with large laboratory instruments, so it has been aiming to develop a "portable" detector. But at the same time, the detector must also achieve accurate and reliable test results, in line with the current "gold standard" of nucleic acid detection of the new crown virus.
How to combine the right technology with a lightweight design, but still without losing a high degree of precision, is one of the challenges faced in the development of this instrument. During the R&D phase, the team was supported by the university and the instrument was produced in PolyU's industrial centre. Thanks to the experts at PolyU's Industrial Centre, who assisted the team in designing and assembling the instruments, they also needed to be fine-tuned and improved. Weighing only about 2.4 kg and measuring 21 cm× 21 cm × 10.5 cm, the current detector can be used continuously for up to seven hours after charging, making it easy to operate in environments outside the laboratory.
Nandu: Is there a follow-up application for this research and development?
Ye Sheping: The detector can be put into use, but there is no plan for mass production at this stage. We welcome relevant government departments or commercial organizations to contact us. The team is also in contact with an international testing and certification body for further market-oriented research cooperation.
Nandu: Will research related to the new crown virus detector continue next? What are the main aspects?
Ye Sheping: The team will soon begin testing on a human sample (no nucleic acid extracted), which is expected to be completed within a few months.
Written by: Nandu reporter Xiao Yunhui
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