Table 2.
Microfluidic SARS-CoV-2 antigen detection kit.
| Study ID | Methods | Fluid Manipulation Technique | Material | Immobilized Antigen/Antibody/Gene | Detected Biomolecules | Detector | Sensitivity | Specificity | Sample Size/Donor/Standard | Limit of Detection (LOD) | Detection Time | Advantages |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Lin 2021 [22] | Fluorescence immunoassay | Centrifugal force | Polycarbonate | FMS coated SARS-CoV-2 capture antibody | SAS-CoV-2 antigen | homemade fluorescence detection analyzer | NR | NR | 10 patient and 9 healthy people | NR | ˂15 min | Portable, rapid, easy to use, on-site detection, high sensitivity, and specificity. |
| Tan 2020 [30] | Microfluidic chemiluminescent ELISA technique | Capillary force | Polystyrene | Capture antibodies to S1 and N | N and S | NanoDrop™ UV-Vis spectrophotometer |
NR | NR | 16 convalescent patients and 3 healthy participants | 4 pg/mL (S) and 62 pg/mL (N) | 40 min | Low time consumption, sensitive, low sample volume requirement, low-detection limit |
| Wang 2021 [31] | Space-encoding microfluidic biochip | Pump | PDMS | Capture antibodies to S and N | N and S | GenePix 4400A Microarray Scanner | NR | NR | 60 serum samples | ~0.3 pg/mL to ~4 ng/mL | ˂10 min (qualitative) 40 min (quantitative) |
60 sample per test, fast, sensitive, Ultralow detection limit |
| Qi H, 2022 [42] | MEA chip based solid−liquid interface capacitance/ trace N-protein detection by microfluidics-coupled capacitive sensor |
DEP force (Pneumatic micropumps) | MEA chip modified with an aptamer | An aptamer for SARS-CoV-2 N protein | SARS-CoV-2 N | Sensor and impedance analyzer | NR | NR | 0.1 mL saliva sample collected from 3 volunteer | 1.26 × 10−6 ng/mL (saliva) 2.16 × 10−6 (plasma) and 1.82 × 10−6 ng/mL, (serum) |
15 s | Wide linear range from 10−5 to 10−2 ng/mL, a real-time, easy-to-operate, label-free, and specific |
| Li Y, 2021 [43] | MXene–graphene field-effect transistor (FET) sensor to create an ultra-sensitive VSTM | NR | PDMS | APTES linked Anti-S IgG | SARS-CoV-2 spike protein purchased from SinoBiological | fabricated MXene− graphene FET sensor | NR | NR | recombinant 2019-nCoV spike protein | 1 fg/mL | ∼50 min | Relatively simple to construct, fast-responding, ultrasensitive, and specific sensor |
| Ge C, 2022 [53] | Microfluidic chip with femtoliter-sized wells, Biotinylated aptamer and β-Galactosidase affinity | Peristaltic pump | PDMS | Capture-SA-β-Gal-linked anti-N IgG Detection- Biotinylated aptamers |
SARS-CoV-2 N | Inverted fluorescent microscope | NR | NR | SARS-CoV-2 N (Suzhou) Biotecnology Co., Ltd.) | 33.28 pg/mL | NR | Simple, cost effective, detection by fluorescence, reusable |
| Li J, 2021[64] | Microfluidic chip with an integrated immunosensor that utilizes dually labeled magnetic nanobeads | Electromagnetic micropump | PET film stacked with a PMMA cartridge on top of an SPGE sensor | Dually labelled magnetic nanobeads with HRP and detection antibody | SARS-CoV-2 N | Microfluidic immunosensor chip | NR | NR | SARS-CoV-2 N (Advaite, Inc.) | 100 pg/mL (5× diluted serum) and 230 pg/mL (whole serum) | <1 h | Portable, simple, and highly sensitive immunosensor |
| S Kim, 2021 [70] | Airborne droplets are captured on the paper microfluidic chip and detected by fluorescent conjugated antibody | Capillary manipulation | Nitrocellulose paper | Detection antibody conjugated with yellow-green fluorescent carboxylated polystyrene particles | SARS-CoV-2 N | Smartphone-based fluorescence microscopic imaging | NR | NR | SARS-CoV-2 Isolate USA-WA1/2020 | NR | <30 min | Low cost, handheld, foldable paper microfluidic assay, rapid virus detection from air droplets |
| Xu J, 2021 [71] | Hydrodynamic filtration with sandwich immunoassay | Syringe pump | PDMS | N-MAb conjugated in white microbead and red nanobead | SARS-CoV-2 N | Naked eye detection | 95.4% | 100% | 93 individuals (48 negatives and 45 positives by qPCR) |
<100 copies/ mL |
NR | Simple to use, point-of-care, reusable and cost-effective chip, |
| Sun M, 2022 [73] | Chitosan-glutaraldehyde cross-linking to coated antibody, and sandwich ELISA for detection | Capillary manipulation | Whatman 3 MM filter paper | Capture-N Specific MAb Detection-HRP-tagged MAb | SARS-CoV-2 N | Camera and ImageJ software | NR | NR | N protein (Guangzhou Qianxun Biotechnology Co., Ltd., Guangzhou, China) | 8 μg/mL | NR | Small-sized chip, simple and easy portable, rapid detection |
Abbreviations: FDG—fluorescein-di-β-D-galactopyranoside; β-gal—β-galactosidase; MEA—microelectrode array; VSTM—virus-sensing transduction material; FET—field-effect transistor; APTES—3-aminopropyl triethoxysilane; LLOD—lower limit of detection; PET—polyethylene terephthalate; PMMA—poly(methyl methacrylate); SPGE—Screen-printed gold electrode.