Table 3.
Other methods and materials used for the detection of SARS-CoV-2
| Biosensing technique | Material selection and design | Biomarker | Limit of detection |
|---|---|---|---|
| Poly (amino ester) with carboxyl groups (PC)-coated magnetic nanoparticles (pcMNPs) – based viral RNA extraction [79] | The magnetic nanoparticles were synthesized using Iron (III) chloride and a co-precipitation method. Then a silica layer was coated on the surface of the magnetic nanoparticles. Then silica-coated magnetic nanoparticles were dispersed into a mixture of 50 mL isopropanol and 0.2 mL of APTES to prepare NH2-MNPs. Finally, a solution containing poly (amino ester) with PC was used to coat amino-modified magnetic nanoparticles with PC | SARS-CoV-2 RNA (N gene) | A 10-copy sensitivity |
| Lanthanide-doped nanoparticles-based lateral flow immunoassay [81] | LNPs were synthesized using the mini emulsion polymerization process to detect anti-SARS-CoV-2 IgG. Mouse anti-human IgG antibody (MHIgG) and rabbit IgG (RIgG) were used to functionalize LNPs. By dispensing a recombinant nucleocapsid phosphoprotein of SARS-CoV-2 onto a nitrocellulose membrane, the specific IgG of SARS-CoV-2 was captured | Anti-SARV-CoV-2 IgG | - |
| Reverse transcription loop-mediated isothermal amplification (RT-LAMP) [83] | A two-color RT-LAMP assay protocol was utilized to detect the SARS-CoV-2 N gene in clinical samples. The color of the phenol-red dye was changed within 30 min of the reaction in the presence of positive clinical samples with a CT of less than 30 | SARS-CoV-2 RNA (N gene) | Cycle threshold (CT) less than 30 |
| Colorimetric Loop-Mediated Isothermal Amplification (LAMP) biosensor [84] | Five LAMP primers sets were designed to detect the SARS-CoV-2 RNA (ORF1a gene and Gene N). DNAs containing these regions were synthesized as gBlocks | SARS-CoV-2 RNA (ORF1a gene and Gene N) | 4.8 copies/μL |
| Artificial intelligence-assisted loop-mediated isothermal amplification (AI-LAMP)-based biosensor [85] | A novel hand-held smart diagnostic device was designed to eliminate any subjectivity related to the operator interpretation of results. To decrease the assay run time of the colorimetric LAMP detection, AI pipelines were used to observe and detect color changes through AI image processing | SARS-CoV-2 RNA | 100 copies of SARS-CoV-2 RNA |