Protection Of RNA By Using Magnetic Carbon Nanotubes And Its Application In Nucleic Acid Detection Of SARS-CoV-2

In 2020,the novel Coronavirus Disease 2019(COVID-19)caused by SARS-CoV-2 swept the world,causing 670 million cumulative cases of infection.RNA is the genetic material of SARS-CoV-2.Therefore,in the process of collection and testing of COVID-19 samples,far distance transportation and improper handling of samples make viral nucleic acid samples easily degrade,which will affect test results and lead to false negative results,causing harm to epidemic prevention and control work and public health.Single-wall Carbon Nanotubes(SCNTs),as a kind of nanomaterial with high specific surface area,can rapidly adsorb single strand nucleic acid to carbon nanotubes by π-π interaction.This study firstly explored the protective effect of SCNTs from the aspects of protective time,protective temperature and effect comparison with different RNase inhibitors,and proved that SCNTs could protect total RNA of E.coli for 96 h under the protective condition of room temperature.The protective effect is comparable to that of commercially available RNase inhibitors,and SCNTs can be stored at room temperature for long periods of time compared to commercially available RNase inhibitors.Scanning Electron Microscope(SEM)and Reverse Transcription Polymerase Chain Reaction(RT-q PCR)was used to explain the principle of SCNTs adsorption of RNase and RNA.It was proved that the protective ability of SCNTs to RNA was realized because SCNTs simultaneously blocked the contact between RNA and RNase.Magnetic Single-wall Carbon Nanotubes(MSCNTs)were constructed based on magnetic solid-phase separation,and a new extraction method for RNA protection and nucleic acid enrichment was established.After building MSCNTs,Fourier Transform Infrared Spectrometer(FTIR Spectrometer),Zeta potential analysis,Malwen particle size analysis and other methods are used to characterize the modification of MSCNTs.200 m M HCl was used to protonate MSCNTs,and 1 m L sample storage solution was used to construct a simulated sample extraction method.Finally,it has been demonstrated by RT-q PCR and Reverse Transcription Loop-medited Isothermal Amplification(RT-q LAMP).It was determined that the optimal dosage of MSCNTs without inhibition on nucleic acid amplification in RT-q PCR and RT-LAMP was 1 μg and 20 μg,respectively,and the use of MSCNTs could reduce the minimum detection limits of RT-q PCR and RT-LAMP by 8-10 times and 50 times,respectively.The establishment of the whole method can save the time of extraction operation,enhance the stability of sample during transportation,improve the sensitivity of virus detection and effectively reduce the occurrence of false negative results.