Table 3.
Examples of interferometric-based methods using different recognition elements. The limit of detection (LOD), calculated as the blank response plus three times the standard deviation, is reported. Alternatively, the measured concentration range is shown between brackets.
| Analyte | Recognition Element | Assay Format | Immobilization | Sensitivity | Sample Matrix | Interf. Type | References |
|---|---|---|---|---|---|---|---|
| Domoic acid | PAb | Inhibition | Covalent binding of domoic acid by active ester chemistry | 2.0 ng/mL (IC50) | Mussel tissue extracts | BLI | [218] |
| Irgarol 1051 | PAb | Binding inhibition | Covalent binding of a derivative onto an APTES functionalized surface | 3 ng/L | Sea water | BiMW | [219] |
| DON | MAb | Competitive | Adsorption of DON-OVA on the sensor chip | 128 µg/kg 737 µg/kg |
Wheat Wheat dust |
BLI | [248] |
| Testosterone | MAb | Binding inhibition | Covalent binding by active ester chemistry of a derivative onto a DAPEG coated surface | 94.4 ng/L | Milk | RIfS | [223] |
| AFM1 | Fab′ | Competitive | Fab′ binding to a mercaptosilane functionalized surface | 5 × 10–7 RIU | Milk | aMZI | [207] |
| Vancomycin | Peptide | Direct | Covalent binding of the peptide to a pSi surface via a carboxy-linker | KD = 1.09 × 10–5 mol/L | - | RIFTS | [249] |
| Testosterone | Aptamer | Competitive | Biotinylated aptamer on streptavidin-coated chip | [2.13–136.63 ng/mL] | - | BLI | [234] |
| Argininamide | Aptamer | Direct | Biotinylated aptamer on avidin-coated chip | 5 µM | - | DPI | [236] |
| Microcystin-LR (MC-LR) | MIP | Direct | Dip coating of the sol–gel matrix | [0.3–1.4 g/L] | Environmental water | FP | [250] |
| Melamine | MIP | Direct | Spin coating | 1251 rad/RIU | - | YI | [208] |
| Methyl-parathion | AChE | Direct | Covalent attachment to a APTES-GLU-functionalized surface | 2.4 × 10−10 M (2.1 nM–47 µM) |
- | ITFS | [208] |
Abbreviations: AChE, acetylcholinesterase; AFM1, aflatoxin M1; aMZI, asymmetric Mach-Zehnder interferometer; APTES-GLU, 3-aminopropyltriethoxysilane-glutaraldehyde; BiMW, bimodal waveguide interferometer; BLI, biolayer interferometry; DAPEG, diamino-poly(ethylene glycol); DON, deoxynivalenol; DPI, dual polarization interferometer; Fab′, antibody fragments; FP, Fabry-Perot interferometer; IC50, half maximal inhibitory concentration; ITFS, interferometric tapered fiber sensor; KD, equilibrium dissociation constant; mAb, monoclonal antibody; MIP, molecularly imprinted polymer; OVA, ovalbumin; PAb, polyclonal antibody; pSi, porous silicon; RIFTS, reflective interferometric Fourier transform spectroscopy; RIU, refractive index unit; YI, Young’s interferometer.