Table 2 Comparison of current miRNA detection techniques.

From: Attomolar sensitivity microRNA detection using real-time digital microarrays

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

  1. *Denotes the calculated LOD levels by extrapolation below the lowest measured concentration.
  2. Significant values in this study are in bold.