Table 2.
Comparison of current miRNA detection techniques.
| Method | Matrix | miRNA | Dynamic range | LOD | Assay duration |
|---|---|---|---|---|---|
| Competition assay based on fluorescence quenching of Au NPs43 | Aldehyde-activated glass slide | miRNA-205 | 3.8 pM–10 nM | 3.8 pM | 7 h hybridization |
| Surface plasmon resonance imaging (SPRI)24 | LNA array | miRNA-16 miRNA-122b miRNA-23b | 10 fM–1 pM | 10 fM | 4 h hybridization |
| Photonic Resonator Absorption Microscopy: Au NP SPR coupled photonic crystal (PC) guided resonance5 | PC-adhered polydimethylsiloxan | miRNA-375 miRNA-1290 | 100 aM–1 pM | 100 aM | 2 h hybridization |
| Electrochemical biosensor based on poly(U) polymerase mediated isothermal signal amplification44 | Electrochemically deposited AuNPs on Au surface | miRNA-319a | 10–1000 fM | 1.7 fM* | 2 h hybridization, 1.5 h reaction time |
| Electrochemical biosensor based on analyte triggered nanoparticle localization and hybridization chain reaction dual amplification45 | Tetrahedral DNA with the recognition hairpin immobilized on a gold electrode | miRNA-17-5p | 100 aM–100 pM | 2 aM* | 2 h hybridization |
| Fluorescence-based Single Molecule Array (Simoa)46 | Capture probes on microbeads | miRNA-16 miRNA-21 miRNA-141 | 1–1000 fM | 0.68 fM* 1.60 fM* 0.58 fM* | 2 h hybridization |
| Digital detection with real-time polarization enhanced SP-IRIS (this study) | MCP2-2F (5%) Copolymer | miRNA-451 miRNA-223 | 100 aM–1 pM 1 fM–1 pM | 6.2 aM* 13 aM* | 0.5 h hybridization |
*Denotes the calculated LOD levels by extrapolation below the lowest measured concentration.
Significant values in this study are in bold.