Table 2.
Electronic tongues containing sensors based on conducting polymer coatings applied in the analysis of food samples.
| Sensor Array | Sample | Use | Multivariate Calibration | Ref. | |
|---|---|---|---|---|---|
| No CP Sensor | CP Sensor | ||||
| SNG-C | PEDOT/Pt | Musts | Discrimination of samples collected at different ripening times | PCA iPLS PLS |
[114] |
| - | PEDOT/Pt | Red wines | Classification of different samples and origin | PCA PLS |
[115] |
| Pt Au |
PEDOT/Pt | Fruit juice | Discrimination between samples from different fruits | PCA PLS-LDA |
[116] |
| IDE PA6/IDE |
PA6/PANI/IDE (0.25–5.0% PANI) | Bovine milk | Discrimination of samples according to tetracycline residue content | PCA | [117] |
| CE AuCE rGO-CE rGO-AuCE |
PANI-CE PANI-AuCE |
Vinegar, sugar |
Multiflavor detection | PCA | [118] |
| C/SPE NiO/C/SPE MWCNT/C/SPE SWCNT/C/SPE Pt |
PANI/C/SPE | Red wine | Phenolic content | PCA | [119] |
| SWCNT/SPCE MWCNT/SPCE |
PPy-DSA/SPCE | White wine | Discrimination according to varietal origin | PCA LDA |
[120] |
| CPE-CoPc CPE-LuPc2 CPE-LuPc2 |
PPy-dopant/Au Dopant: SO4, DSA, FCN, AQDS, PWA, TSA |
Red wine | Evaluation of chemical adulteration | PCA PLS |
[121] |
| GdPc2/CSPE DyPc2/CSPE CSPE |
PPy-dopant/CSPE Dopant: FeCN, NP, Mo |
Beef | Determination of ammonia and putresceine | PCA PLS-LDA |
[122] |
| - | PPy- dopant/Pt Dopant: DSA, H2SO4, FCN, AQDS, PWA, TSA |
Beer | Evaluation of bitterness and alcoholic strength | PCA PLS |
[123] |
| - | PPy-dopant/Pt Dopant: FCN, NP, PWA, H2SO4, MO, AQS |
Olive oil | Evaluation of bitterness | PCA PLS |
[124] |
| - | PPy-dopant/SPCE Dopant: DSA, SO4, FCN |
Wine | Classification of wines according to vintage year | PCA LDA |
[125] |
| Graphite-epoxy PtNPs CuNPs |
PANI PPy |
Wine | Classification of wines and recognition of the oxygenation effect | PCA | [126] |
AQDS: anthraquinone-2,6-disulfonic acid, disodium salt; AQS: anthraquinone-2,6-disulfonic acid; CNT: carbon nanotubes; CoPc: cobalt phthalocyanine; CPE: carbon paste electrode; CuNPs: copper nanoparticles; DSA: sodium 1-decanesulfonate; FCN: potassium hexacyanoferrate (II); IDE: interdigitated electrodes; LDA: linear discriminant analysis; LuPc2: lutetium bis-phthalocyanine; MO: sodium molybdate; MWCNT: multi-walled carbon nanotubes; PA6: polyacrilamide; PANI: polyaniline; PCA: principal component analysis; PEDOT: poly-(3,4-ethylenedioxythiophene); PLS: partial least squares regression; PPy: polypyrrole; PWA: phosphotungstic acid; PtNPS: platinum nanoparticles; rGO: reduced-graphene oxide; SNG-C: sonogel-carbon; SPCE: screen-printed-carbon electrode; SPE: screen-printed electrode; SWCNT: single-walled carbon nanotubes; and TSA: p-toluenesulfonic acid.