Table 2.
Summary of paper-based biosensors.
| Method | Type of detection | Signal element | Recognition element | Target | Sample | Detection limit | Ref. |
|---|---|---|---|---|---|---|---|
| Colorimetry | Optical Optical Optical |
Gold nanoparticles Gold nanoparticles Gold nanoparticle, carbon black, and magnetic nanoparticles |
Antibody Antibody Antibody |
Exosomal MICA and CD9 Exosomal CD9, CD81, and CD63 Exosomal CD9, CD81, and CD63 |
Melanoma (Ma-Mel- 55 and Ma-Mel-86c) cells and human serum Melanoma (Ma-Mel- 86c) cells and human Plasma Human plasma |
5 × 107 exosomes/µl 8.5 × 105 exosomes/µl 3.4 × 106 extracellular vesicles/µl |
(111, 134, 134, 135) (134, 136) |
| Fluorescent | Optical | Upconversion nanoparticles (UCNPs) and gold nanorods (AuNRs) |
Split aptamer | Exosomal CD63 | Hepatocellular carcinoma (HepG2) cells |
1.1 × 103 particles/µl | (137) |
| ICA | Optical Optical |
Gold nanoparticles Quantum dots |
Antibody Antibody |
Exosome biomarkers Exosome biomarkers |
Breast tumor (MCF-7) Cells Oral squamous carcinoma (Cal27) cells |
1.3 × 103 particles/µl 2 × 103 particles/µl |
(14, 138) |
| p-ELISA | Optical | HRP-linked secondary antibody | Antibody | Exosomal CD9 and CD63 | Lyophilized exosome standards and human serum | 9.29 × 1010 particles/ml | (139) |