posted on 2021-08-23, 16:33authored byMeiting Yang, Yidan Tang, Lijuan Qi, Sicai Zhang, Yichen Liu, Baiyang Lu, Jiaxue Yu, Kun Zhu, Bingling Li, Yan Du
Coronavirus
diseases such as the coronavirus disease 2019 (COVID-19)
pandemic, caused by severe acute respiratory syndrome coronavirus
2 (SARS-CoV-2), pose serious threats. Portable and accurate nucleic
acid detection is still an urgent need to achieve on-site virus screening
and timely infection control. Herein, we have developed an on-site,
semiautomatic detection system, aiming at simultaneously overcoming
the shortcomings suffered by various commercially available assays,
such as low accuracy, poor portability, instrument dependency, and
labor intensity. Ultrasensitive isothermal amplification [i.e., reverse
transcription loop-mediated isothermal amplification (RT-LAMP)] was
applied to generate intensified SARS-CoV-2 RNA signals, which were
then transduced to portable commercial pregnancy test strips (PTSs)
via ultraspecific human chorionic gonadotropin (hCG)-conjugated toehold-mediated
strand exchange (TMSE) probes (hCG-P). The entire detection was integrated
into a four-channel, palm-size microfluidic device, named the microfluidic
point-of-care (POC) diagnosis system based on the PTS (MPSP) detection
system. It provides rapid, cost-effective, and sensitive detection,
of which the lowest concentration of detection was 0.5 copy/μL
of SARS-CoV-2 RNA, regardless of the presence of other similar viruses,
even highly similar severe acute respiratory syndrome coronavirus
(SARS-CoV). The successful detection of the authentic samples from
different resources evaluated the practical application. The commercial
PTS provides a colorimetric visible signal, which is instrument- and
optimization-free. Therefore, this MPSP system can be immediately
used for SARS-CoV-2 emergency detection, and it is worthy of further
optimization to achieve full automation and detection for other infectious
diseases.