Table 2 Representative nanomaterials (NMs) for COVID-19 treatment, immune system boosting and diagnosis

NMs for COVID-19 Treatment

Polydopamine-poly (ethylene glycol) nanoparticulates

Encapsulates DNase-1 to degrade cell-free DNA, potently inhibits NETosis factors in blood samples from COVID-19 patients and also enhances survival in a sepsis model

[242]

Nanorods coated with cell membrane

Prevent infection with hACE2 available on the cell membrane

[243]

Thin shell polymer

Encapsulate catalase to degrade free radical oxygen

[244]

NMs for COVID-19 immune system boosting

Liposomes

Delivered a recombinant trimeric spike as a vaccine. It is a single-dose intranasal vaccination; it induces IgA production in the mucosa

[245]

Self-assembled protein NPs with virus-like particle core

Display several distinct RBDs in vaccine form. The RBDs are linked to NPs via SpyTag: SpyCatcher; various RBDs induce cross-reactivity against different coronaviruses

[246]

Saponin-based nanoemulsion named Matrix-M1

Supply adjuvant activity for a recombinant spike protein vaccine. The M1 matrix is a mixture of two saponin-based fractions to balance adjuvant and adverse effect activities

[247]

Self-assembled protein NPs with ferritin core

Present recombinant RBD and/or heptad repeat (HR) subunits of spike on the surface of protein NPs as a vaccine. The spike is bound to the NPs via Spy Tag: Spy Catcher. HR can induce cross-reactivity with other coronaviruses

[248]

NMs for COVID-19 diagnosis

Colloids gold-NPs

Detection of antinuclear IgM in blood on a lateral flow strip. The test is rapid and takes only 15 min to be read with the naked eye

[249]

Gold-NPs conjugated to hACE2

Detecting the viral particle in serum samples. The test is rapid and takes only 15 min to complete; read with a microplate reader or smartphone-connected device

[250]

Gold-NPs conjugated to antisense oligonucleotides and a graphene layer

Detection of viral RNA in nasal swab or saliva samples. The test is rapid, with a 5-min incubation time after extraction of viral RNA; detection of the electrochemical signal on a biosensor chip

[251]

Selenium NPs

Detection of anti-nucleoprotein IgG and IgM in blood on a lateral flow strip. Testing is rapid and takes 10 min; can be read with the naked eye

[252]

Magnetic NPs functionalized with streptavidin

Detection of anti-spike IgG in blood via afiltration column. The reading is achieved by means of a portable magnetic reader

[253]

Polymer NPs

Detection of viral RNA on a lateral flow strip after RT-LAMP amplification. The proposed test is readable with the naked eye

[254]

Nanoflakes of reduced-graphene-oxide

Sensing anti-spike and anti-RBD antibodies on a 3D printed test chip. Anti-spike and anti-RBD antibodies were immobilized on the surface of the nanoflakes, which are connected to gold electrodes; the test chip provide its reusability easy regeneration and smart reading tool with a smartphone

[255]

Cobalt-functionalized TiO₂ nanotubes

Electrochemical biosensor detection of RBD antigen. The measured signal is based on rapid electrochemical detection in 30 s without the need of antibody immobilization

[256]

Polystyrene-NPs

Screening for anti-nucleoprotein IgG in blood on a lateral flow test strip. Prompt test in ten minutes; using a portable fluorescence reader as detector

[257]